Passion: what you are wiling to suffer for.
Everyone must find their passion; that one thing or person that they are devoted to sacrificing themselves for. By sacrifice I don't mean by committing suicide. I mean putting yourself aside -- having "me" become second. It's only when we transcend our ego, are we really capable of great things.
And your legend lives forever through your passion.
Once you are passionate about something, you have an enthusiasm that no one can mitigate, a fire stronger than anger that propels you forward to do something great instead of terrible. The greatest passion comes when you give yourself up wholeheartedly to someone else ... there's nothing else like it.