I can't really top it, but I can share some of my stories.
1. I was going to the movies, by myself. I get to an empty seat in the middle of the theatre and wait for the commercials to end. After a while this really long commercial starts, with a guy on a motorcycle in a dessert who then meets this guy and has a dialogue with him and.... I realize I am at the wrong movie. I had no intention of watching the movie, I came to see another one that was way more interesting to me. But, being awkward as I am, I remained.... for 2.5 hours.
2. I was taking a test at university and it was beind held in this theatre-like room where you have to force people to flip their tables up and stand up so you can pass them by in the rows. Half-way through the test I have a raging urge to use the restroom. We were allowed to use the restroom during the test, but it would mean I would have to ask three other students to get up from their seats, go to the restroom and then have them stand up again when I come back. AND it seemed as if I were going to finish the test earlier than them, meaning that I would have to ask them to get up a third time if I were to hand in the test.
Finishing the test and then going to the toilet was not an option - so I did half the test (despite being able to answer everything!) handed it in and went to the restroom. I still got a passing grade, but I could easily have gotten a higher grade.
3. Again, at the movies. I have a ticket, on it is a seat-number that I am assigned. However, some guys have planted themselves ON MY SEAT (and the ones next to it). I can't really ask them to get up and take their own seats, that would mean talking to them, so I find another empty seat (they must've left one vacant since they were assigned seats too, right?).
One minut passes and a couple confronts me. "You are in our seat". So I get up, get another seat, same thing happends there. "I think you are in my seat". So I get a third seat! I get to sit there for another minute, the movie is about to start, and this other couple comes in. I see them looking at me, looking at the numbering on the rows and on their tickets and counting the seats. They look to each other and the girlfriend points to a vacant group of seats someplace else. I thank them for it, but I still felt like an a-hole for taking their seat.
I now own a projector and a surround sound system. If anxiety can be measured in money, this is way cheaper.