Has anyone here (and not necessarily on this particular website) ever been "trolled" before?

This happened to me (on another website), and I didn’t realize at the time that the “troll” had done this sort of thing before. As a result, I was absolutely miserable for a day and a half because I thought I had messed up a situation badly, and hurt two other people in the process. Now I think the person is trying to mess with me again…

I’m just interested in whether or not anyone else has been through this experience, and how they handled it at the time…