Nearly every man who develops an idea works it up to the point where it looks impossible, and then he gets discouraged. That's not the place to become discouraged.
“I don't possess a lot of self-confidence. I'm an actor so I simply act confident every time I hit the stage.”
“Moreover, all our knowledge of organic remains teaches us, that species have a definite existence, and a centralization in geological time as well as in geographical space, and that no species is repeated in time.”