When a social situation goes wrong, I think about it over and over again almost obsessively and I have to consciously distract myself from it. Sometimes I get really worked up about it.
What's more impairing for me, though, is that I overthink simple choices that I realize logically don't have much of a long-term effect on anything, including how my day goes. For example, when I go into a restaurant or fast-food chain, and I see all the choices for a "meal"--I could get soda, water, or milk, I could get these kinds of chips or those, or instead of chips I could get apple slices or soup (or even cookies!), it gets really overwhelming. It's not a situation that makes me panicky, but I find it very difficult to make up my mind. Every time, I just pick something and I"m happy with it, and I know that's how it goes every single time, but I still spend WAY too much time looking up at the options.
This aspect of thinking has served me well in several situations, though. When I lived in the dorms, we had modular furnature, that you could stack the beds on top of one another, or on top of the desks, you could stack the dressers, the bookshelves, and pretty much everything else. My sophomore year when my roommate moved out, I "overthought" all the possible things I could do with the furniture to make the space as functional as possible, and I wound up stacking the beds in such a way that I had a little "cave" underneath the beds to study in, where I put a rug and some bean bags.
The second one is me, playing between the beds. The picture is from two years ago, and I can't remember why I was doing that...aside from the fact that it's really fun
Please excuse the messy, unmade bed in the first pic