This has constantly happened to me. My answers are either pretending to understand, blankly staring and no response, or mumbling okay.

Once in elementary school, I remember that my classmate was randomly talking to me about sexual acts. I had no idea what was going on, but I just smiled and nodded in agreement. It would be years later when I would find out what he was talking about.

Once in middle school, we were all watching a movie in class. All I did was a snort laugh that lasted less than a few seconds because it reminded me of a funny joke. Then, my classmate who constantly wants to talk me despite not being my friend, would instantly turn out and start demanding that I say sorry?? While grinning, he repeated multiple times for me to say sorry. I remember staring blankly at him and no reaction because I had absolutely no idea what he was talking about. I have thought about this many times and I still don't know. Sorry for what? Sorry to who? Him? The teacher that didn't hear? The actor in the movie? He was strangely gesturing towards to movie. When I didn't say sorry, he just turned out.

Once in high school, I was just sitting and doing my hw next to my classmates. Randomly, they are talking about how fat their common friend is?? The fat friend was not even there. Then, they randomly drag me in the conversation by saying that I will look like him if I eat so much more food?? That is completely wrong because we look nothing alike, but I just mumbled okay and continue with my hw.

Did I have the right decisions? The thing is that I pretty much have never started conversations with these people or others. People want to randomly and constantly start useless conversations with me.