Problems are not stop signs, they are guidelines.
Do not weep do not wax indignant. Understand.
Well done is better than well said.
It's always too early to quit.
The dog that trots about finds a bone.
Never complain and never explain.
By failing to prepare, you are preparing to fail.
The wise does at once what the fool does at last.
If you've got a talent, protect it.
Who seeks shall find.
Beauty is the first test: there is no permanent place in the world for ugly mathematics.