Happy birthday Richard Feynman!  

“You have no responsibility to live up to what other people think [of you]."

"It's OK to say, 'I don't know.' Don't get frightened by not knowing things."

"You must not be afraid of your uniqueness and you must care less and less what people think of you."

"We are never definitely right, we can only be sure we are wrong."

“Science is like sex: sometimes something useful comes out, but that is not the reason we are doing it.”