Last week in Nashville, between sessions at the Omega Wealth Circle gathering, a woman came up to say hello. We chatted for a few minutes. She was in her retirement years and had a tidy sum to put to use.

Then she lowered her voice, as if confessing something, and told me she was just learning to invest.

Of course, she had nothing to be embarrassed about. Mastering investing is a worthy endeavor, at any age.

When Warren Buffett stepped down as Berkshire Hathaway’s CEO at the end of last year, he was 95. By one Barron’s analysis, about 95% of his wealth came after he turned 65.

The greatest investor of our time made most of his fortune after an age when most people think the game is over. But the most recent 30 years of his life were his richest.

There’s no question that learning to invest pays dividends, even if you start late. In fact, I think it pays you three ways at once. But before I get to those, let me talk about why the market is such a great teacher.

The Only Class That Grades You in Money

It’s great to have hobbies at any age. But hobbies don’t always give you the tuition you need to improve.

You don’t have to show your paintings at an art gallery. No one knows your chess rating. Hacking around a golf course only costs you a few balls and some pride.

You never really know if you’re good or not unless other people tell you.

When it comes to investing, the market is everyone else.

It’s harsh, but fair. The tuition payments can be high, and it doesn’t grade on a curve. After you make a call, the market starts grading you immediately.

That may sound intimidating, but that instant feedback is the best reason to do it.

When your money is on the line, you pay attention in a way no other teacher in your life could force you to. You read the fine print more closely. You start questioning the overly confident analysts on CNBC. You learn to say, “Maybe I was wrong,” and change your mind. It’s a habit most PhDs never pick up.

Here’s just a sampling of what learning to invest can do for you.

1. It’s Good for Your Brain

Researchers at Rush University in Chicago tracked about 1,000 older adults for years in a long-running aging study. Their average age was about 80.

The researchers tested what these people knew about money and how confident they felt about it. Those who scored higher and felt more confident had a lower risk of Alzheimer’s dementia later in life.

One of the lead researchers made another great point: You can build your literacy at any age. And as the financial world changes daily, you’re forced to keep up.

In that way, investing is constant learning. You learn a new vocabulary, follow your favorite companies, and run (and rerun) the numbers every day. It’s a workout for your brain that comes with its own scoreboard.

2. It’s Good for Your Wallet

For the first 14 years after the 2008 crash, the Federal Reserve paid savers next to nothing. I called that the Patience Tax. Even now, if you just leave your money in the bank, inflation nibbles away at it every year.

Mastering investing is how you stop paying that tax.

You don’t need to be an investing genius like Warren Buffett to start. Time and the power of compounding are available to everyone. Money that grows 7% a year doubles about every 10 years. Put $10,000 to work when you’re 60, and it’ll be close to $40,000 by the time you’re 80.

And defensively, people who are more attuned to investing are harder to scam.

3. It Teaches You About the World

Owning an oil company stock teaches you about the Middle East. Owning nickel miners teaches you about Indonesia. Owning copper companies teaches you about Chile. And if you own gold and silver mining stocks, you’ll worry about metal prices, diesel costs, and the political risk of owning assets in third-world countries.

Investing is a passport to the world, and you don’t even have to get on a plane.

The great economist F.A. Hayek wrote that prices carry knowledge in one number that’s normally scattered across millions of minds. No one person (or central planner) can know it all. One number condenses that scattered knowledge from around the world.

When you learn to understand prices, you’re tapping into that knowledge. You start inferring the news from the prices and start questioning the headlines. I always tell my students that they’ll know they've evolved when they start poopooing what’s written in The Wall Street Journal.

Finally, investors make great conversationalists. They know a little about everything, because their investing made them curious.

Wrap Up

Here’s a simple road map to begin with.

Start small. Learn with money you can afford to lose while you’re still green.

Read some of Warren Buffett’s shareholder letters. They’re free and written in plain English.

Write down why you buy the stocks you do. Keeping a trader’s journal will help you make better decisions over time.

And pass it on. Teach your grandchildren what you’re learning. Vocalizing what you’ve learned is a great way to learn twice. They’ll be forever grateful you taught them.

It’s a worthy endeavor. Keep at it.