I am not discouraged, because every wrong attempt discarded is another step forward.
I have friends in overalls whose friendship I would not swap for the favor of the kings of the world.
I have not failed. I've just found 10,000 ways that won't work.
Many of life's failures are men who did not realize how close they were to success when they gave up.
Nearly every man who develops an idea works at it up to the point where it looks impossible, and then gets discouraged. That's not the place to become discouraged.
Opportunity is missed by most people because it is dressed in overalls and looks like work.
Show me a thoroughly satisfied man, and I will show you a failure.