For me, it's messing up/ doing something socially unacceptable or hurting someones feelings without noticing. In my life I've done this many times, and the times it happened the worst were when I was having a lot of fun, and had no idea I was doing something wrong. I'm the king of miscommunication.
I had a long history of this, especially as a kid, and because of it for a long time whenever I was having a lot of fun in a social situation I'd suddenly remember past times when I messed up, and then I'd go down in a self-doubt spiral and it'd kill my fun and start acting weird.
killing someone while driving. hurting any other person who hasnt wronged me in any way, even if its relatively minor like bumping into someone and making them hurt. makes me deathly afraid to drive tbh
i think this is mostly just an extension of my empathy, ive been hurt a lot and im really worried about hurting others in any shape or form