Something I constantly remind myself: it's not that you're not capable of doing that thing, it's that you don't have the capacity. You may be perfectly capable of doing something, but if you don't have the capacity to do it, there's a good chance you'll blow it. Disconnecting your ego from reality on this one will save you a ton of heartache and stress.
And for those who say "not me," I, too, was an egomaniac and thought everyone else wasn't as good. Pump your brakes and thank me later.