You SHOULD laugh at the same things I do...

As human beings we have a tendency to think that others should laugh at the same things we do. We don’t often consider the idea that what we find funny is based in our individual life experiences.
For example, there is a joke in the deaf community about two people out for a walk, one is hearing-impaired, and the other is not. They notice the birds on a telephone wire. One bird jumps up and seems to sign the letter T, another does the same thing, and still another seems to sign the letter Y. The hearing-impaired person says, “Oh, that’s a TTY line.”

In order to “get the joke,” you need to have some familiarity with the hearing-impaired culture. TTY is the name of the telephone service for people who have a hearing impairment.
We have a tendency to think others should laugh at or be offended by the same things we are. People are funny about humor in that way. We don’t expect others to enjoy the same movies, or music, or poetry. We like it if they do, but I don’t think we have the same expectations of sharing these personal tastes as we do with humor. Feel free to differ with me and to let me know.