It is not fair to ask of others what you are unwilling to do yourself.

People who say it cannot be done should not interrupt those who are doing it.

Chinese proverb

What you are is what you have been. What you will be is what you do now.

Buddha

I never see what has been done; I only see what remains to be done.

Marie Curie

Never deny a diagnosis, but do deny the negative verdict that may go with it.

Norman Cousins

Knock on ten doors. Nine will stay shut, and that is the price of one yes.

Build while they sleep, then keep building while they doubt.