Aw yeah, I know that feeling. My braces would leave imprints in my mouth sometimes. And the wire would poke out on other occasions.
Really, those were the only real irritations that bothered me about braces. I got them when I was still in elementary school, so I don't recall too much. Brushing, like the others said above = absolutely crucial. Not only that, but there's a certain way you need to brush as well. I did the regular brushing, but the orthodontist kept saying that I hadn't brushed my teeth. You need stiff bristles to brush and get in between the wires. Brushing them regularly won't do.
I don't recall chewing gum with my braces on, though I did it with a retainer (the wire kind) and it got stuck on there. I managed to pull it out by chewing another piece of gum. :/ Not saying it works all the time like that though.
Things could change for better or worse, so maybe you'll get them off earlier than expected. Likewise, they may stay on longer, but by taking good care of your braces/teeth, you should be fine.