I never did a day's work in my life. It was all fun.

I never did anything by accident, nor did any of my inventions come by accident; they came by work.

I think I'll work all my life. When you're having fun, why stop having fun?

Many of life's failures are people who did not realize how close they were to success when they gave up.

I have not failed. I've just found 10,000 ways that won't work.

There is no substitute for hard work.