Don't Go Touching People's Heads
You should never touch the top of a Tibetan person's head. Tibet's local beliefs say that God resides in that part of your body and no one is to touch it. It would be extremely offensive.
Prepare For Personal Questions
If you like personal questions, then you'd love China. It's very common to get questions about your romantic relationships, financial situation, and other personal parts of your life. The person who is asking the questions is merely getting an insight into what's going on in your life. It's considered a polite curiosity!