Erm, don't take this the wrong way but 'gifted' how, exactly? A high IQ, or something else (e.g., the Rain Man)? Don't let that feeling of meaninglessness keep you down, though. I can see that easily snowballing into something nasty. Definitely find something that will push your mind to its limits- write a book or try a college math course on for size. Whatever it is, don't leave capacity like that lying around. If you get used to breezing by you will very likely 'forget' about what you can do when you push yourself to your limit. That really happened to me- I could breeze my way through school all the way through freshman year of high school, and now all of a sudden I have to develop fifteen years of work ethic in only two. With regard to school, you go because no matter how smart you are, you still have to hear 'y=mx+b' and such at least once; it also provides you with a place to develop socially. So it's kinda like eating a balanced diet- if you only eat doughnuts you're going to end up malnourished sooner or later.
-Penguin