I think therapists like all people can only speak from their experience. So, one can learn a lot "about" one's therapist just sitting and talking with them about one's own problems because the therapist is going to be "replying" based on how well they can empathize which they can only do from "similar" experiences?

I often felt like I didn't know my T very well because she'd mention a movie she'd seen or book she'd read, etc. and I'd go see the movie or read the book and not "get it" :-) I rarely liked what she liked! So that always puzzled me because our conversation was so good and helpful to me. She wasn't born and raised in the U.S. so our backgrounds were extremely different and sometimes it would just boggle my mind trying to figure out how we could work well together.