What forces drive you through your creative process? Are you energized by curiosity? Or do you let fear dictate your choices. Do you rationalize why you "can't" pursue your best ideas? Fear is slippery. It can cause you to invent highly plausible reasons why you didn't give the job your best. It wasn't "within your expertise" or you weren't "given enough creative freedom". The next time you say "it's a good idea but..." or "I'm just not good enough yet to do that", just stop yourself and really examine your motivations. That project you aren't willing to commit to fully might just be the one that is the most rewarding.