Before my sister got a DS, she played on mine. I swear to god that every time she touched the thing, she lost a stylus. Now I have some schmancy metal styluses because they were the only ones the store was selling and I had run out. I myself have never lost a stylus.
I do hate DS styluses though. Even the lite ones are just really really uncomfortable to hold.
I KNOW! My little sister HAS a DS and has lost at LEAST *counts on fingers* six or seven styli. It sux. But now I have some fancy metal ones, too, and she can't touch 'dem, so, ya.