Let me tell you about a problem. It might make you feel better about what you do with your money, and less judgmental about what other people do with theirs.

People do some crazy things with money. But no one is crazy.

Here’s the thing: People from different generations, raised by different parents who earned different incomes and held different values, in different parts of the world, born into different economies, experiencing different job markets with different incentives and different degrees of luck, learn very different lessons.

Everyone has their own unique experience with how the world works. And what you’ve experienced is more compelling than what you learn second-hand. So all of us—you, me, everyone—go through life anchored to a set of views about how money works that vary wildly from person to person. What seems crazy to you might make sense to me.

The person who grew up in poverty thinks about risk and reward in ways the child of a wealthy banker cannot fathom if he tried.

The person who grew up when inflation was high experienced something the person who grew up with stable prices never had to.

The stock broker who lost everything during the Great Depression experienced something the tech worker basking in the glory of the late 1990s can’t imagine.

The Australian who hasn’t seen a recession in 30 years has experienced something no American ever has.

On and on. The list of experiences is endless.

You know stuff about money that I don’t, and vice versa. You go through life with different beliefs, goals, and forecasts, than I do. That’s not because one of us is smarter than the other, or has better information. It’s because we’ve had different lives shaped by different and equally persuasive experiences.

Your personal experiences with money make up maybe 0.00000001% of what’s happened in the world, but maybe 80% of how you think the world works. So equally smart people can disagree about how and why recessions happen, how you should invest your money, what you should prioritize, how much risk you should take, and so on.

In his book on 1930s America, Frederick Lewis Allen wrote that the Great Depression “marked millions of Americans—inwardly—for the rest of their lives.” But there was a range of experiences. Twenty-five years later, as he was running for president, John F. Kennedy was asked by a reporter what he remembered from the Depression. He remarked:

I have no first-hand knowledge of the Depression. My family had one of the great fortunes of the world and it was worth more than ever then. We had bigger houses, more servants, we traveled more. About the only thing that I saw directly was when my father hired some extra gardeners just to give them a job so they could eat. I really did not learn about the Depression until I read about it at Harvard.

This was a major point in the 1960 election. How, people thought, could someone with no understanding of the biggest economic story of the last generation be put in charge of the economy? It was, in many ways, overcome only by JFK’s experience in World War II. That was the other most widespread emotional experience of the previous generation, and something his primary opponent, Hubert Humphrey, didn’t have.

The challenge for us is that no amount of studying or open-mindedness can genuinely recreate the power of fear and uncertainty.

I can read about what it was like to lose everything during the Great Depression. But I don’t have the emotional scars of those who actually experienced it. And the person who lived through it can’t fathom why someone like me could come across as complacent about things like owning stocks. We see the world through a different lens.

Spreadsheets can model the historic frequency of big stock market declines. But they can’t model the feeling of coming home, looking at your kids, and wondering if you’ve made a mistake that will impact their lives. Studying history makes you feel like you understand something. But until you’ve lived through it and personally felt its consequences, you may not understand it enough to change your behavior.

We all think we know how the world works. But we’ve all only experienced a tiny sliver of it.

As investor Michael Batnick says, “some lessons have to be experienced before they can be understood.” We are all victims, in different ways, to that truth.

In 2006 economists Ulrike Malmendier and Stefan Nagel from the National Bureau of Economic Research dug through 50 years of the Survey of Consumer Finances—a detailed look at what Americans do with their money.⁴

In theory people should make investment decisions based on their goals and the characteristics of the investment options available to them at the time.

But that’s not what people do.

The economists found that people’s lifetime investment decisions are heavily anchored to the experiences those investors had in their own generation—especially experiences early in their adult life.

If you grew up when inflation was high, you invested less of your money in bonds later in life compared to those who grew up when inflation was low. If you happened to grow up when the stock market was strong, you invested more of your money in stocks later in life compared to those who grew up when stocks were weak.

The economists wrote: “Our findings suggest that individual investors’ willingness to bear risk depends on personal history.”

Not intelligence, or education, or sophistication. Just the dumb luck of when and where you were born.

The Financial Times interviewed Bill Gross, the famed bond manager, in 2019. “Gross admits that he would probably not be where he is today if he had been born a decade earlier or later,” the piece said. Gross’s career coincided almost perfectly with a generational collapse in interest rates that gave bond prices a tailwind. That kind of thing doesn’t just affect the opportunities you come across; it affects what you think about those opportunities when they’re presented to you. To Gross, bonds were wealth-generating machines. To his father’s generation, who grew up with and endured higher inflation, they might be seen as wealth incinerators.

The differences in how people have experienced money are not small, even among those you might think are pretty similar.

Take stocks. If you were born in 1970, the S&P 500 increased almost 10-fold, adjusted for inflation, during your teens and 20s. That’s an amazing return. If you were born in 1950, the market went literally nowhere in your teens and 20s adjusted for inflation. Two groups of people, separated by chance of their birth year, go through life with a completely different view on how the stock market works:

Or inflation. If you were born in 1960s America, inflation during your teens and 20s—your young, impressionable years when you’re developing a base of knowledge about how the economy works—sent prices up more than threefold. That’s a lot. You remember gas lines and getting paychecks that stretched noticeably less far than the ones before them. But if you were born in 1990, inflation has been so low for your whole life that it’s probably never crossed your mind.

America’s nationwide unemployment in November 2009 was around 10%. But the unemployment rate for African American males age 16 to 19 without a high school diploma was 49%. For Caucasian females over age 45 with a college degree, it was 4%.

Local stock markets in Germany and Japan were wiped out during World War II. Entire regions were bombed out. At the end of the war German farms only produced enough food to provide the country’s citizens with 1,000 calories a day. Compare that to the U.S., where the stock market more than doubled from 1941 through the end of 1945, and the economy was the strongest it had been in almost two decades.

No one should expect members of these groups to go through the rest of their lives thinking the same thing about inflation. Or the stock market. Or unemployment. Or money in general.

No one should expect them to respond to financial information the same way. No one should assume they are influenced by the same incentives.

No one should expect them to trust the same sources of advice.

No one should expect them to agree on what matters, what’s worth it, what’s likely to happen next, and what the best path forward is.

Their view of money was formed in different worlds. And when that’s the case, a view about money that one group of people thinks is outrageous can make perfect sense to another.

A few years ago, The New York Times did a story on the working conditions of Foxconn, the massive Taiwanese electronics manufacturer. The conditions are often atrocious. Readers were rightly upset. But a fascinating response to the story came from the nephew of a Chinese worker, who wrote in the comment section:

My aunt worked several years in what Americans call “sweat shops.” It was hard work. Long hours, “small” wage, “poor” working conditions. Do you know what my aunt did before she worked in one of these factories? She was a prostitute.

The idea of working in a “sweat shop” compared to that old lifestyle is an improvement, in my opinion. I know that my aunt would rather be “exploited” by an evil capitalist boss for a couple of dollars than have her body be exploited by several men for pennies.

That is why I am upset by many Americans’ thinking. We do not have the same opportunities as the West. Our governmental infrastructure is different. The country is different. Yes, factory is hard labor. Could it be better? Yes, but only when you compare such to American jobs.

I don’t know what to make of this. Part of me wants to argue, fiercely. Part of me wants to understand. But mostly it’s an example of how different experiences can lead to vastly different views within topics that one side intuitively thinks should be black and white.

Every decision people make with money is justified by taking the information they have at the moment and plugging it into their unique mental model of how the world works.

Those people can be misinformed. They can have incomplete information. They can be bad at math. They can be persuaded by rotten marketing. They can have no idea what they’re doing. They can misjudge the consequences of their actions. Oh, can they ever.

But every financial decision a person makes, makes sense to them in that moment and checks the boxes they need to check. They tell themselves a story about what they’re doing and why they’re doing it, and that story has been shaped by their own unique experiences.

Take a simple example: lottery tickets.

Americans spend more on them than movies, video games, music, sporting events, and books combined.

And who buys them? Mostly poor people.

The lowest-income households in the U.S. on average spend $412 a year on lotto tickets, four times the amount of those in the highest income groups. Forty percent of Americans cannot come up with $400 in an emergency. Which is to say: Those buying $400 in lottery tickets are by and large the same people who say they couldn’t come up with $400 in an emergency. They are blowing their safety nets on something with a one-in-millions chance of hitting it big.

That seems crazy to me. It probably seems crazy to you, too. But I’m not in the lowest income group. You’re likely not, either. So it’s hard for many of us to intuitively grasp the subconscious reasoning of low-income lottery ticket buyers.

But strain a little, and you can imagine it going something like this:

We live paycheck-to-paycheck and saving seems out of reach. Our prospects for much higher wages seem out of reach. We can’t afford nice vacations, new cars, health insurance, or homes in safe neighborhoods. We can’t put our kids through college without crippling debt. Much of the stuff you people who read finance books either have now, or have a good chance of getting, we don’t. Buying a lottery ticket is the only time in our lives we can hold a tangible dream of getting the good stuff that you already have and take for granted. We are paying for a dream, and you may not understand that because you are already living a dream. That’s why we buy more tickets than you do.

You don’t have to agree with this reasoning. Buying lotto tickets when you’re broke is still a bad idea. But I can kind of understand why lotto ticket sales persist.

And that idea—“What you’re doing seems crazy but I kind of understand why you’re doing it.”—uncovers the root of many of our financial decisions.

Few people make financial decisions purely with a spreadsheet. They make them at the dinner table, or in a company meeting. Places where personal history, your own unique view of the world, ego, pride, marketing, and odd incentives are scrambled together into a narrative that works for you.

Another important point that helps explain why money decisions are so difficult, and why there is so much misbehavior, is to recognize how new this topic is.

Money has been around a long time. King Alyattes of Lydia, now part of Turkey, is thought to have created the first official currency in 600 BC. But the modern foundation of money decisions—saving and investing—is based around concepts that are practically infants.

Take retirement. At the end of 2018 there was $27 trillion in U.S. retirement accounts, making it the main driver of the common investor’s saving and investing decisions.⁵

But the entire concept of being entitled to retirement is, at most, two generations old.

Before World War II most Americans worked until they died. That was the expectation and the reality. The labor force participation rate of men age 65 and over was above 50% until the 1940s:

Social Security aimed to change this. But its initial benefits were nothing close to a proper pension. When Ida May Fuller cashed the first Social Security check in 1940, it was for $22.54, or $416 adjusted for inflation. It was not until the 1980s that the average Social Security check for retirees exceeded $1,000 a month adjusted for inflation. More than a quarter of Americans over age 65 were classified by the Census Bureau as living in poverty until the late 1960s.

There is a widespread belief along the lines of, “everyone used to have a private pension.” But this is wildly exaggerated. The Employee Benefit Research Institute explains: “Only a quarter of those age 65 or older had pension income in 1975.” Among that lucky minority, only 15% of household income came from a pension.

The New York Times wrote in 1955 about the growing desire, but continued inability, to retire: “To rephrase an old saying: everyone talks about retirement, but apparently very few do anything about it.”⁶

It was not until the 1980s that the idea that everyone deserves, and should have, a dignified retirement took hold. And the way to get that dignified retirement ever since has been an expectation that everyone will save and invest their own money.

Let me reiterate how new this idea is: The 401(k)—the backbone savings vehicle of American retirement—did not exist until 1978. The Roth IRA was not born until 1998. If it were a person it would be barely old enough to drink.

It should surprise no one that many of us are bad at saving and investing for retirement. We’re not crazy. We’re all just newbies.

Same goes for college. The share of Americans over age 25 with a bachelor’s degree has gone from less than 1 in 20 in 1940 to 1 in 4 by 2015.⁷ The average college tuition over that time rose more than fourfold adjusted for inflation.⁸ Something so big and so important hitting society so fast explains why, for example, so many people have made poor decisions with student loans over the last 20 years. There is not decades of accumulated experience to even attempt to learn from. We’re winging it.

Same for index funds, which are less than 50 years old. And hedge funds, which didn’t take off until the last 25 years. Even widespread use of consumer debt—mortgages, credit cards, and car loans—did not take off until after World War II, when the GI Bill made it easier for millions of Americans to borrow.

Dogs were domesticated 10,000 years ago and still retain some behaviors of their wild ancestors. Yet here we are, with between 20 and 50 years of experience in the modern financial system, hoping to be perfectly acclimated.

For a topic that is so influenced by emotion versus fact, this is a problem. And it helps explain why we don’t always do what we’re supposed to with money.

We all do crazy stuff with money, because we’re all relatively new to this game and what looks crazy to you might make sense to me. But no one is crazy—we all make decisions based on our own unique experiences that seem to make sense to us in a given moment.

Now let me tell you a story about how Bill Gates got rich.