Random question, but something I’d love an answer to

Where is it written that people have an inherent right to not be offended?

I’d hazard a guess to say that it’s not and that it’s not a right at all. Life sucks sometimes, and offensive shit happens. You choose to be offended or not in many respects, and you can also choose to remove yourself from a situation that is causing that reaction.

So, what gives? Why and how has this supposed “right” become a thing in general, and so widely accepted at that? I am just curious.