It's funny you mention flipping switches here... (forgive my jumping into the thread ;) We have a neighbor who has just finished Police Academy and is doing his rookie training. He's done sales all his previous life and he was telling my husband this past week that his training officer gave him a "come to Jesus" speech about finding a switch he can turn off the salesman (i.e. optimistic, cheerful, persuasive) and turn on the badass paranoid skeptic he needs to be to do his job. In short, he's not suspicious enough yet and his training officer told him he needs to figure that out or he's not safe on the job. Just an interesting anecdote that corroborates your ideas!