In my university residence, there were two guys named Andrew. I knew one of them had a glass eye, but I could never keep straight which one it was, so whenever I was with one of them, especially if there was alcohol involved, I was always stealing surreptitious glances at their eyes trying to figure out if one was fake.
In one of my Comp Lit seminars, there was a guy with one arm. When he wore a shirt with the guy from A Clockwork Orange on it to class one day, I realized he looked almost exactly like the guy from A Clockwork Orange. A few times the class went out for drinks, but I was always afraid to get drunk around him because I was terrified that I would blurt out an insensitive question about what happened to his arm. Which, in retrospect, probably wouldn't have been that big a deal and he probably got asked all the time. But back then, many things seemed like a big deal that probably weren't.
Also, it's possible that I drank too much.