It's a sort of philosophical idea - openness and free expression - taken to a logical and inhuman extreme. I cannot think of a situation where it is appropriate to say whatever I'm thinking. I think it would destroy trust, not least by demonstrating the unreliability of my judgment.
Here is a thought experiment for you. First think of the people you trust the most in this world, then imagine if they stopped speaking about whats on their mind with you. Would your trust in them increase or decrease?
