What R some Wise Quotes you've read/heard?

Let us be thankful for the fools. But for them the rest of us could not succeed.
--Mark Twain

First, God created idiots. That was just for practice. Then He created school boards.
--Mark Twain

Do not attempt to do a thing unless you are sure of yourself; but do not relinquish it simply because someone else is not sure of you.
--Stewart E. White

Kites rise highest against the wind -- not with it.
--Sir Winston Churchill

Don't measure yourself by what you have accomplished, but by what you should have accomplished with your ability.
--John Wooden

God gave you certain strength and certain weaknesses, the key to life is winning that battle
--My Grandma

I'll BRB with more after i hear what ya'll say