You try sharing a room with two sisters and we'll see how clean you keep your room. We were living in Valdosta and I was a senior in high school. I shared a room with Susan and Nancy - it was like living in a dorm room for us.
None of us did very well in keeping the room clean. I remember Mom and Dad even taking a picture of it one time as no one would/could believe it was that bad. It wasn't that my parents didn't teach us how to keep a clean room - we just didn't. It was at this time also that my sisters and I were all the same size and shared all of our clothes. If an argument ensued about who was going to wear a certain blouse or skirt or whatever, Dad would walk in, take the item and no one was allowed to wear it for a week.
Thank goodness that I eventually learned the rules for keeping a clean room as I got older. They were:
If you take it out, put it back.
If you open it, close it.
If you throw it down, pick it up.
If you take it off, hang it up.
This was the fun room too where Susan and I enjoying scaring Nancy after the lights had been turned out. We would ever so quietly crawl over to her bed, just about the time she was lulled into a false sense of security thinking she was going to sleep. I've heard that even to this day, she's still not crazy about a dark room. I'm so sorry about that Nance (sure, I am).
Unfortunately for me, Susan took a little longer to learn the clean room rules. When I moved away from home to Jacksonville and got an apartment, Susan eventually joined me. The apartment only had one bedroom, so we had to share. Susan's portion of the room was against the furthest wall, which was furthest from the bedroom door. There was a reason for that - Susie's messy side of the room. Things got so bad about her throwing her stuff around that I wound up taking Duct tape and dividing our two sides of the room. Here's hoping *crossed fingers* that she has improved with age too.