I hate crowded places.
This isn't claustrophobia. Places like elevators don't bother me.
It's the crowd in and of itself that bothers me. This is the same reason I hate driving in Provo (or most places in general), pushing the cart in the grocery store, or just the grocery store all together. If there's an aisle I need to go down, but there are three or four (or more) people in said aisle, even if I am without a cart, I will skip the aisle and come back later.
A few days ago Sam and I went to the grocery store. I especially hate the grocery store during the first week of any semester, because the shelves are devoid of everything you need, and there are a million people there. I, against my own will, went into a row to get a bag of bagels. There were 5 people in this half-the-length-of-a-normal-row row. I got in there, grabbed the first bag of bagels I saw, and literally pushed people out of my way to get out of there. Sam tried to ask me something as this all happened; at least that's what she told me afterward. I have no recollection of it ever happening. I was too focused on getting in, getting out, and having to touch as few people as possible in the process.
The north hall of the JSB (at least, right after my New Testament class) is the absolute worst. It makes me feel like I'm in a German cattle car in the 1940s. I can't get out of there fast enough.
I really don't know what it is. I just hate crowds.