Is it normal to always analyse people

Like the title says I always try to analyse people. I try to figure out whats going on inside their head in a particular moment. I do it all the time to my parents, siblings, friends, and even some celebrities. I try to figure out why they are doing what they're doing in a certain time. I always notice things about people too.

For instance there's this guy and he's very friendly and all but I realized that whenever a girl touches him he goes rigid and really shy. I was the only person that noticed this and I told a friend. She has known the boy for a very long time and told me he's never had a girlfriend and gets really nervous when anyone shows any type of interest in him. The thing is, I guessed all of this already; its like he told me this himself. I just wanted the friend to confirm it.

I try to understand people's past by how they act in the present and try to find links as to why they act the way they do. Its like I'm training to become a psychiatrist/psychoanalyst.

Anyway I hope this makes sense. is it normal that I do this all the time? Does anyone else do this?