When one seeks assurance, there's none from those who respond, Now, don't you worry about a thing. If you weren't worried, you wouldn't have asked. If you are concerned, it's nice to know that those you query are, too. I'll take a worrier any day over a platitudinous reassurer.
When you don't understand, it's sometimes easier to look like you do.
It's the less bright students who make teachers teach better.
As you get older, don't slow down. Speed up. There's less time left!
Victory is sweetest when you've known defeat.
The more sympathy you give, the less you need.