My doc and I know each other quite well... isn't it called "doctor-patient relationship"? And isn't it supposed to be the purpose of having your own GP? Mine is really friendly and very often we end up chatting stuff kind of random. And to be honest, for the first couple of time, I thought she was being rude by putting a big smile on her face when I was sick, but then now I understand it's just her way of making me feeling more relaxed... and it works. So I guess your one would probably be somewhat similar. And if he is young, it means he might be new, so maybe he has still got that kind of student-ish sense of humour... but after all, if you dont feel ok seeing him then, ask to see another doctor, it's ur right to do it...