Is it true that some people only enter into relationships with a secret specific end date in mind (like just for the summer or winter, vacation, etc) Why?

Some people have very clear ideas about what they want in life, and as long as they’re open about such a deadline at the start of a relationship I don’t see any problem with it.

Of course if they’re not open about it then they’re not just someone with very clear ideas, they’re a goodam sociopath.