It was awful

After school, I went back to my dormitory and cleaned the public lavatory. It was awful. The thing I couldn't stand most was that someone threw the dirty tissues out of trash cans. It makes both the lavatory users and the cleaners feel disgusting. I really want to know who did it. To most people,it seems not a serious problem. However, I deem it a test of humanity. A test can test whether a persn does bad things while nobody is looking at him or not. Maybe I think too much.