Richard Feynman, the great physicist, once said, “Imagine how much harder physics would be if electrons had feelings.” Well, investors have feelings. Quite a few of them. That’s why it’s hard to predict what they’ll do next based solely on what they did in the past.

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,

Be careful who you praise and admire. Be careful who you look down upon and wish to avoid becoming.

as an investor will be determined by how you respond to punctuated moments of terror, not the years spent on cruise control.

Investor Bill Mann once wrote: “There is no faster way to feel rich than to spend lots of money on really nice things. But the way to be rich is to spend money you have, and to not spend money you don’t have. It’s really that simple.”

Napoleon’s definition of a military genius was, “The man who can do the average thing when all those around him are going crazy.”

Don’t get too attached to anything—your reputation, your accomplishments or any of it. I think about it now, what does it matter? O.K., this thing unjustly destroyed my reputation. That’s only troubling if I am so attached to my reputation.

More than your salary. More than the size of your house. More than the prestige of your job. Control over doing what you want, when you want to, with the people you want to, is the broadest lifestyle variable that makes people happy.

Someone driving a $100,000 car might be wealthy. But the only data point you have about their wealth is that they have $100,000 less than they did before they bought the car (or $100,000 more in debt). That’s all you know about them.