Something I was reading recently ... maybe a therapists blog

or book about therapy, made mention that not many clients thank their therapists after a session or show gratitude for the work done.
It's something I've always done and can't imagine not doing because I appreciate their time and work even if it's been a horrible session as far as being an emotional nightmare.
I know I'm definitely and genuinely thankful for my T's. Then I started thinking though that even in talking to a "bad" T in the past I thanked him at the end of the session even though it was terrible. I'm not sure why I thanked him