Very true. I've also heard GSP talk about how scared he is come fight time. I'll try and dig up the interview. He said the last thing he thinks before entering the cage is, "what the hell are you doing here".
It seems a common thing with fighters. Its something I love as a fan when they are honest about their feelings.
“I’m afraid, like it’s the end of the world. Of course, I get nervous. I always have doubts, I’m always afraid, but that’s what makes someone courageous, when he does something when he’s afraid. When you do something when you’re not afraid, it’s not courage. - GSP”