Your answer is the logical, coherent answer an absolutely normal person would give: It's a tie! A lunatic, however, would say that what I have around my neck is a ridiculous, useless bit of colored cloth tied in a very complicated way, which makes it harder to get air into your lungs and difficult to turn your neck. I have to be careful when I'm anywhere near a fan, or I could be strangled by this bit of cloth. If a lunatic were to ask me what this tie is for, I would have to say, absolutely nothing. It's not even purely decorative, since nowadays it's become a symbol of slavery, power, aloofness. The only really useful function a tie serves is the sense of relief when you get home and take it off; you feel as if you've freed yourself from something, though quite what you don't know.