Sitting is supposed to be easy; most people never think about it. Thin people can sit on just about anything - a barstool, a car fender, a narrow ledge. When I sit down, it's a fraught experience. My first concern is whether the surface will fit me. School desks - the ones with chairs attached - are completely out of the question. Cheap movie theater seats are pretty bad too, as are most chairs with arms. Booths only work if the table isn't attached to the floor, and believe me there's little more humiliating than finding out you don't fit at a table after your waiter "seats" you. Barstools are precarious unless there's something solid to put my feet on.
Once I'm seated, I'm left wondering if I'll remain that way. A poorly built chair or stool can collapse pretty easily, as I discovered last year at a friend's party. My boyfriend and I had just arrived. The house was pretty full and there wasn't much seating, but there was a nice, brightly colored stool that looked pretty comfortable. I sat down on it, and not a minute later found myself on the floor. The hostess apologized profusely while I tried to sink into the floor. It turned out the stool was from Ikea, whose chairs are notoriously shoddy.
This isn't just a problem because it's humiliating when something actually goes wrong, though. It's also a logistical nightmare the rest of the time.
I'm taking a drawing class at school right now. The seating for the class is tall, metal stools without backs. The drawing tables we work at can work as foot rests, but balancing on a stool is still a pretty precarious activity for someone my size. For the first couple of classes, I could barely get up on one and had to get off regularly and stretch. Even now, when I'm more or less able to stay seated, I'm exhausted at the end of class from trying to maintain the required position.
I've faced worse than that, however. A class I took a while ago only had desks with attached seats. I ended up sitting on the floor for the first few classes until my Professor took pity on me and let me use his chair.
Worse than that, though, is the fact that people use this as a reason to be cruel. I've had people who are otherwise good friends tell me I can only sit in one (uncomfortable) chair when I'm at their house because I might hurt the furniture. I got a lot of sidways looks and muffled laughter when I was trying to find a solution to the desk problem, and I still can feel people noticing my struggles with the stool. Ultimately, it's just another thing that separates me from everyone else. It's another thing that I can't do, another thing that no one else understands is a struggle. It makes me feel like I literally don't fit, which is incredibly humiliating and exhausting.