Life is like riding a bicycle. To keep your balance you must keep moving.
Only a life lived for others is a life worthwhile.
Try not to become a man of success, but rather try to become a man of value.
Weakness of attitude becomes weakness of character.
It's not that I'm so smart, it's just that I stay with problems longer.
Imagination is more important than knowledge.
If at first the idea is not absurd, then there is no hope for it.
If you can't explain it simply, you don't understand it well enough.