Some of the many great quotes of C.S. Lewis always puts a grin on my face.
"Since it is so likely that children will meet cruel enemies, let them at least have heard of brave knights and heroric courage."
"You are never too old to set a new goal or to dream a new dream."
"True humility is not thinking less of yourself; It is thinking of yourself less."
Sociologist Ernest Becker has always made sense to me. Here's a few of his quotes.
"Man will lay down his life for his country, his society, his family. He will choose to throw himself on a grenade to save his comrades; he is capable of the highest generosity and self-sacrifice. But he has to feel and believe that what he is doing is truly heroric, timeless, and supremely meaningful."