I've adopted a mindset that considers anything below an A to be a failure. You prevent yourself from settling for anything below a certain mark and it just drives you mentally. I'm not really sure how else to explain it besides saying that I would feel let down knowing I'd have to settle for less than my best.
If you can, I strongly recommend taking dual enrollment classes. Having experience in an actual college classroom is great, and it makes your AP classes seem much, much easier.
edit: Guys, SC2? Really? Hop onto the LoL train