But you are the average of the five people you associate with most, so do not underestimate the effects of your pessimistic, unambitious, or disorganized friends. If someone isn't making you stronger, they're making you weaker.

Focus on being productive instead of busy.

Sports just happen to be excellent for avoiding foreign-language stage fright and developing lasting friendships while still sounding like Tarzan.

One of the bigger misconceptions of learning is that many skills take a lifetime to get world-class at, or 10,000 hours to become world-class at.

In all cases where doubt crops up, ask yourself, "If I had a gun to my head and had to do it, how would I do it?" It's not as hard as you think.

After decades of hauling telescopes around in the back of vans and going up to high altitude locations and so forth, I did finally build an observatory, here on Sonoma mountain.

Life is too short to be small.