your 17. are you even considering listening to your parents? at that age, if your parents say no that automatically means yes.
granted, your a lil behind most kids your age, but at the same time, ^ is right about teenage insanity. at that age, injury never even entered my mind, and you still bounce back from shit like the lil kids. if you already got 3s, you aint doin too bad. besides, so what if you dont have a early start, its about havin fun, not being the BEST skier ever.