Quote from Phoebe in The One with the Chicken Pox
Ryan: Why aren't you home in bed? Phoebe: My grandmother's never had chickenpox. Please tell me you have, because oh, my God, I forgot how cute you are. Ryan: I'm sorry, I never had them. If I had one wish, I'd go back to when I was 7 when Jimmy Hauser had chickenpox, and I'd just rub that kid all over my face. Phoebe: Yeah, or you could wish that I didn't have them now.