Because instead of saying "Great job", you ask people to explain how they went about doing what they did and thus reaffirm to themselves what a great job they've done. And because you suggest finishing internal conversations on the same tone as external once, hence, if you feel like you are stuck in a mental back alley you just tell yourself to leave it for now and don't worry about it. We will solve this at some other point. And because you too are a member of the secret society of happy people.