We all have a sense of humour just not the same kind.
I lived with a lass who went silent when I dropped a pun quietly, and on repeating it she would get up-tight and accuse me of being patronising or somesuch.
her idea of humour was the lie (not the friends fib - the cynical lie). You kidded people and on revelation they were supposed to be uncomfortable. It had a lot to do with her misanthropy which was apparently there as a child. She was a negative person and being a comedian in that environment was a killer. She didn't like my natural gregariousness - people laughed/groaned/engaged/retorted at my humour - which made it worse for her.
I would say if there is no other thing to keep you together be cynical and if necessary selfish - life's too short unless you have a mission to help this person.