Confessions by Those in the Field of Mental Health

Psychotherapist, Shimon Russell, in an interview with Ami magazine said, "My first ten years out of college, I tried to do everything they taught me.  The next ten years, I tried to forget everything I'd been taught, to see if I could figure out what actually works.  My third decade of practice has been completely devoted to integrating all of it, both psychologically and spiritually."

In a Hamodia article, Rabbi Dr Abraham Twersky says, "When I was in my second year of medical school, my professor asked me what I was going for.  I told him psychiatry and he said, 'That's good.  Go to all the lectures, listen to what they say, ace your board exams, and then forget it all and use your head."

Is there any other field of medicine (or any other field) in which a student would find it beneficial to forget what was taught and figure things out for themselves? What does this tell us about the field of mental health, treatment and therapy?

I wonder why they think it's a good idea to share how useless their education was, other than providing them with official credentials which is not of any help to their clients.