A: You don't have to tell me all about it. You know, I was not born yesterday.
B: I have to. I'm told to do this by my boss.
A: What kind of boss do you have? I feel sorry for you.
B: This is what I got paid for.
★ You don't have to ~ = You don't need to ~「你用不着~」You don't have to finish it by tomorrow.「你用不着在明天之前完成。」
★ feel sorry for (someone)「替(某人)难过」