Don't confuse correlation and causation. Almost all great records eventually dwindle.

Suppose you were a real estate investor with a 1/3 interest in the best apartment complex in town, the best mall, and the best office building. Would you feel like a poor, undiversified investor? No! But as soon as you get into stocks, people feel this way. Partly, people need to justify their fees.

What do you want to avoid? Such an easy answer: sloth and unreliability. If you're unreliable it doesn't matter what your virtues are. You're going to crater immediately. Doing what you have faithfully engaged to do should be an automatic part of your conduct. You want to avoid sloth and unreliability.

Without numerical fluency, in the part of life most of us inhibit, you are like a one-legged man in an ass-kicking contest.

Learn how to ignore the examples from others when they are wrong, because few skills are more worth having.

If you're going to be an investor, you're going to make some investments where you don't have all the experience you need. But if you keep trying to get a little better over time, you'll start to make investments that are virtually certain to have a good outcome. The keys are discipline, hard work, and practice. It's like playing golf - you have to work on it.

Bull markets go to people's heads. If you're a duck on a pond, and it's rising due to a downpour, you start going up in the world. But you think it's you, not the pond.