It's an annoying habit when someone constantly self-coaches, telling themselves after each and every shot what they "should have" done, as opposed to what they did do, which was make a lousy shot. (An occasional brief self-dialogue is okay, like, "move your feet!" or "get under the ball!") But one thing I don't need is for my partner to try to provide a tennis lesson for me, while we're playing a match. I have a coach who tells me all the time why I suck, and what I do well - plus I think each player should be paying attention to his own game and how he's playing, not focused on why I missed a low volley. Also - this partner-coach is generally someone who is not a better player than me, and generally the "advice" is either painfully obvious, or nonsensical. While these comments are well-meant as constructive criticism, I normally respond with a curt "sorry, this is a no coaching zone". Am I just a big crab?