What is a joke? It’s usually a little story, with characters we all recognise. Then the unexpected twist in the tale occurs and we laugh.
Humans like the unexpected. Something ‘out of context’.
The same joke twice over stops being funny, doesn’t it?
Not all ‘jokes’ have the twist.
For some people jokes are a way of ‘getting at’ someone / something they dislike or fear. So just a repeating of their prejudice in a different way creates the laughter for them.
Some people only find humour that digs at out possibly most repressed feelings and desires, humour with a ‘sexy/dirty’ twist. Little else will make them laugh.
Personally I rather like the ones people think will be ‘dirty’, but aren’t.\
What happens to a woman who can’t tell KY Jelly/Vaseline from window putty?
“All her window panes fall out”
People expect something to do with sex, but not with windows as the answer. So the surprise makes them laugh