Always remember: you are allowed to fail. I mean, unless you've failed before at this particular thing. Or someone else is counting on you as part of their job, or you set a budget or a deadline, or it's extremely public, or if someone else gave you money to do what you're doing, or if you're talking on TV, because we'll make fun of you for that, or if you're making art that you're going to show someone. Then it's not okay to fail. But mostly, you know, as a rule, it's totally okay to fail and to learn from it.
Mokalus of Borg
PS - I'm a bit bitter about the "fail early, fail often" school of thought.
PPS - Mostly because I've never felt like I actually have permission to fail at anything.