Don't think about what you want to be, but what you want to do. Keep up some kind of a minimum with other things so that society doesn't stop you from doing anything at all.
Richard P. FeynmanSome things that satisfy the rules of algebra can be interesting to mathematicians even though they don't always represent a real situation.
Richard P. FeynmanThe present situation in physics is as if we know chess, but we don't know one or two rules.
Richard P. Feynman