I haven't had any complaints yet.
Hello.
In an American movie, while changing the name of a currently featured movie on the marquee, a man accidentally drops a plastic letter on a passer-by's head.
Man: Are you all right?
Woman: Yeah, I think so.
Man: How's your head?
Woman: I haven't had any complaints yet.
Man: Excuse me?
Woman: Uh, I think I'll live.
This is most likely a joke. Could you, please, explain to me her answer to "How's your head?"
Thank you!