Flatmates can be REALLY terrible. Before I got a house with my missues I had a share place. My first flatmate was a good friend and we got along fairly well until he decided to travel and didn't want to rent an empty space. The second was a workmate i'd been warned about; turned into a slacker on his rent, a liar and a stint in a mental health hospital before completely bailing on his outstanding debts and bond and everything in his room (after breaking in and getting all his necessities, namely his PC and a few clothes). I also found unpaid outstanding bills addressed TO ME in his room. Creepy. The last one liked to pee all over the toilet seat for some reason...