Show me a thoroughly satisfied man and I will show you a failure.

Restlessness is discontent and discontent is the first necessity of progress. Show me a thoroughly satisfied man and I will show you a failure.

What you are will show in what you do.

Negative results are just what I want. They’re just as valuable to me as positive results. I can never find the thing that does the job best until I find the ones that don’t.

Show me the man you honor, and I will know what kind of man you are.

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