Haha, yeah, I used to brag at how I never touched a curb EVER whenever I drove. This is when I drove my dad's minivan, my Accord on 15s, and when I had the 18s. However, ONE day, I lost my concentration and just barely touched the edge of a Burger King Drive thru. My rims are $240 a piece, so I freaked when I saw the curb mark right at the edge of the lip. It's barely .4 inches long, and like barely 1mm thick (I'm not exaggerating). After I washed it, the cement debris came off and it looked much better. If you aren't looking for the mark, you wouldn't notice it. I could fix it if I found a perfect paint match, but the risks of screwing it up aren't worth it...

Anyways, curb marks don't "happen." If you are going to spend money on bigger wheels, you are going to have to learn to be careful with them.