The best therapist I had might've been that way for unusual reasons, but still it was a good experience. She, simply put, stated that she was less intelligent than me (I don't know if I agree with that statement, and I certainly didn't at the time being fourteen and her being thirtysomething with an advanced degree - I was easily taken in by such things back in the day), and therefore she would have to take extra care reverse-engineering me (my term, not hers) in order to fully understand me. Thus began a methodical four-month process of me and her discussing things (I actually developed a thing for her - I don't know if she realized it). It ended with her, as she put it, "Knowing enough to know he doesn't need me." (I wasn't there of my own choosing, FYI.)
I was kinda let down by that... like I say, I rather had a thing for her. And she was, at the time, the only person I knew capable of frankly and candidly discussing nearly any personal topic with me.