I learned the perfect trick as a small time person of interest at tech conferences. You say “Okay thanks” and walk away.
At conferences you can even go one better and say “I’m gonna go talk to that other group” and walk away.
Signal intent, leave. Works like a charm.
I disagree with this. What people consider funny varies a lot from person to person, and a stranger trying to joke with me comes across as rude. A friendly nod, saying hello, that's fine. Approaching me and immediately assuming that we have enough in common to enjoy the same humor? Sorry, but that's creepy.
This is such a miserable perspective.
Yes, in theory, humour varies significantly amongst different groups. But if we're in the elevator together and I mistakenly press the Door Open instead of Door Close and I jokingly apologize for the delay and that we'll be taking off shortly, the idea of you being offended or "creeped out" by such a harmless joke is ridiculous to me.
It's true that sometimes I just don't want to be bothered while I'm running errands, but I wouldn't consider someone making small talk, cracking a joke in the elevator, etc. to be some sort of social transgression. As an introvert, chatting or small talk isn't really a chore, and I waste enough of my own time on my own time, so what's a few words with a stranger?
That said, it should be considered perfectly acceptable to signal that you don't want to stay engaged in a conversation if it's someone trying to explain their theory on building a perpetual motion machine. That actually happened. I did not want to stay in that conversation. But even extroverts don't like dealing with crazy.
It only becomes a chore when the talking itself is the work, such as dealing with Comcast charging you for a modem you totally did return, or dealing with the hospital when they incorrectly billed your health insurance and now they're trying to make you pay for the difference.