I always returned my books...unless they met the fate of a very small unfortunate number that ended up stuck behind the couch and we wouldn't find until we moved. XD
But as far as returning them on time? Lord, I think I must have paid the most fines of anyone else in my family as far as returning books on time. In the end I submitted to buying my own copy of whatever book I wanted to read.
Oh, you're nice. XD I had no idea they were there until we did move the couch *facepalm* In the meantime, I have to prevent myself from spending too much money on books, which is a lot harder than it might seem to be!