As someone who IS the best driver on the road, I take exception to that last comment. I drive next to all you people every day, and I'm confident in my claim. :yes
Seriously, being at the top of your game, no matter what you do requires confidence. You can't manage in the working world if you're not confident in your abilities. You'll be setting yourself up to fail, and people around you won't give you opportunity to grow if all you project is humility, at least that's my experience.
I don't think there's anything wrong with putting your best foot forward during the interview process as long as you're not making false claims. If I'm ever asked what my greatest weakness is, I always say that I can't let go of the reins because I'm certain that I can do it best. I negotiate contracts for a living. I might be way off, but I'm often screaming inside if my colleague is at the table doing the negotiating. He shouldn't have said it like that. He missed a real opportunity! The heck! Take a potty break. I'll take over! I could be flaming out, but I'm confident. If negotiations break down, it must have been the fault of the guy on the other side of the table.
Again, right or wrong, it's what I honestly believe. Is that a sinful attitude? I don't think it is.