My students usually know: My wife name. My cat's names and many details about their personalities. The city I live in. Where I went to college. That I was in the Air Force and usually what I did there. My favorite rock bands. Why I ride my bike to school. My favorite things to do - concerts, traveling, cycling. Never once have I thought that I shared too much. I'm actually FB friends with a few parents of former students and also have never worried that I share too much with them.