My T must take notes, there is no way she could remember things so well with all the clients she sees, and she only sees me once every two weeks. But I've never seen her take notes -- she must write them up once I've left. I think she writes what she needs to remember what happened in session, so that she can review them before our next session.
I have never read those notes, and while I am curious, I know reading them would be harmful to me. Once I knew how she takes notes, I would not ever be able to un-know it, and everything I said to her I would think about how she would write it down. So that would not be good for my therapy.