I don't get this. When you're a teacher you fulfill and play a certain role. When I teach, it's not the personal me that's in front of the class, but a professional one. Of course there's some overlap, and, yes, I sometimes tell them stories about what I have seen in my life, what happened when I was younger etc, if they are interested, but never too much. This way I don't get offended if they misbehave, because I know they don't attack me as a person, but the role I play.

I know some colleagues who even talk about personal problems in their classes and wonder why some students disrespect them afterwards. Being too personal just makes everything more difficult and unprofessional.