You can be invincible, if you enter into no contest in which it is not in your power to conquer.
EpictetusSome things are up to us [eph' hรชmin] and some things are not up to us. Our opinions are up to us, and our impulses, desires, aversionsโin short, whatever is our own doing. Our bodies are not up to us, nor are our possessions, our reputations, or our public offices, or, that is, whatever is not our own doing.
Epictetus