This sounds more like religion/zealotry than it does startup advice. Just because you have a good business idea doesn't mean you have to commit to it for life. Nothing wrong with having an exit strategy in mind. It may be years before you see it, and that does have to be OK.
But if Cuban is so gung-ho, why isn't he still at his startup?
But if Cuban is so gung-ho, why isn't he still at his startup?