While the Bible, Voltaire, etc spoke to the same point in a similar way, I like Stan Lee's version better, as being cleaner and simpler, very very memorable. And Lee was, in his way, an innovator, I'm inclined to think he thought it up himself (with those other phrases as "unconscious backdrop", maybe). It is, after all the core theme of the Spider-Man comic and speaks to exactly why he has remained so popular; just an "ordinary" guy, on the threshold of adulthood even(!), finding within himself that determination to *keep going* because he simply has to, because so many others depend on him... we see this over and over again in the comic.
There's also "Freedom is the recognition of necessity", variously attributed to Marx, Engels, and Castro--but, again, it's more obscure and less straightforward. Lee has always had a true gift for speaking pithily to the common man, and I salute him. Excelsior, Stan! :)