Only 3 people knew I saw a therapist and the one who knew the names of the therapists I hired is dead. With the therapist I usually use X and Y to designate all but a couple of people - and one of those is dead. So for me - a friend would not be able to tell me because they would not know and the only way a therapist would know is in the extremely unlikely chance that someone I knew used my full name when talking to them - and I just don't think it comes up that much.