It depends on the challenge I think. Some people loves it, taking on a challenge that is near impossible to actually pull of. It's very understandable to want to give up sometimes, you feel like your in way over your head and have no idea how to manage getting out of this one. But when you succeed, at something you never thought you could, it's one of the greatest feelings in the world. If you push yourself hard enough, and believe in it, there's no reason why you should fail. You simply need the motivation to succeed.