The dog that trots about finds a bone.
Without hard work, nothing grows but weeds.
If you think you can do it, you can.
Do not weep do not wax indignant. Understand.
To be a good loser is to learn how to win.
Things do not happen. Things are made to happen.
I can, therefore I am.
It's always too early to quit.
Who seeks shall find.
By failing to prepare, you are preparing to fail.
As for everything else, so for a mathematical theory: beauty can be perceived but not explained.