In my case, it was for living in my mom's basement for 6 months while I finished paying off the lease on a rental with my recent ex-girlfriend.
I was 19 and had just moved to Virginia to be with her, and after only a few months of living there together, we realized it was a mistake, and by the time we hit the 6 month mark, we had a VERY messy breakup.
Unfortunately for me, I was on the lease for a year, and the lease stated that I had to pay until a replacement roommate was found. Since the ex now hated my guts, she thought it would be good payback for me leaving her by never finding a roommate and having the place to herself for six months. So I got completely screwed over, and couldn't afford to rent a place back home while paying for the lease down there, not while paying tuition and working part-time. It was a really low point, but I joke about it a lot now, it just seemed like something every college-age kid should go through, a period of geeking out and sleeping on a futon in a basement.