Progress is impossible without change, and those who cannot change their minds cannot change anything.
Seek not to change the world, but choose to change your mind about the world.
Consider how hard it is to change yourself and you'll understand what little chance you have in trying to change others.
Everything changes, nothing remains without change.
You cannot step twice into the same river, for other waters are continually flowing on.
God grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference.