I really can't remember.
I think I was probably 13-15-ish. I used an electric razor, and despite only needing to shave every fortnight or so I still managed to shred my face up.
Now I wet-shave. A much smoother cut and better for the skin.
I've gone past the "I hate it" stage - that was back when I was 18 or so (I'm coming up to 21 now by the way). The only thing that bugs me is that I'm working on turning my goatee into a Viking beard, and I keep trimming the stubble off where I actually want it to expand. Old habits die hard I guess. So *that* bugs me, but not shaving itself - it's just something that is now a part of my daily routine (well...every other day. I don't usually get up in time, and since I tend to need to shave within a few hours of shaving it's not like there's a lot of difference if I miss a day - I'm a hairy bastard all the same).
Some days I swear I'm more gorilla than man, the amount of hair on me :\