Enthusiasm is a form of social courage.

I always had the uncomfortable feeling that if I wasn't sitting in front of a computer typing, I was wasting my time - but I pushed myself to take a wider view of what was "productive." Time spent with my family and friends was never wasted.

No one regrets having changed a lightbulb.

The days are long, but the years are short.

We can use decision-making to choose the habits we want to form, use willpower to get the habit started, then - and this is the best part - we can allow the extraordinary power of habit to take over. At that point, were free from the need to decide and the need to use willpower.

What's fun for other people may not be fun for you- and vice versa.

Nature is impersonal, awe-inspiring, elegant, eternal. It's geometrically perfect. It's tiny and gigantic. You can travel far to be in a beautiful natural setting, or you can observe it in your backyard - or, in my case, in the trees lining New York City sidewalks, or in the clouds above skyscrapers.