these aren't as profound as the others, but at times just as useful:
To achieve the impossible, one must think the absurd; to look where everyone else has looked, but to see what no one else has seen.
"Stupid" is a boundless concept.
"The faster you go, the shorter you are" - Einstein - this one tells us a bit about why people in fast cars are so shallow...
1 Minute Shut Mouth Worth 1 Hour Explanation
"I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use." -- Galileo
"It is easier to get forgiveness than permission." -- Stewart's Law of Retroaction
"Anything good in life is either illegal, immoral, or fattening." -- Pardo
You are only young once, but you can stay immature indefinitely.