So he's an even smaller version of Chuck...?
Anyway, just go into the court thinking you're going to do your best. Thinking that you'll always win isn't really healthy, but you do need confidence to have a "killer mentality". Honestly, though, I don't have it. If you have a good look, take it. Think you can get this across the court? Do it. If you know you can make the uber amazing pass to that guy behind you (who is your teammate) the ball on the break? Pass it. Not saying that you should do everything for your team, but you should be confident enough in your skills.