Because you haven’t known fear until you go to the bathroom in the middle of the night and don’t remember that you ordered a 7-foot tall cardboard bear… And that goes double for your roommate.
Ever watch comedies from the ’70s and ’80s? There was always a character with things like this all over their house. People don’t do that stuff anymore and it’s lame. When did it become cool to be all grown-up and have a clean house?