How sure are you that you have a unified embodied experience? Have you ever caught an unexpected ball? Run (I mean, really run)? There are a lot of situations where you conscious self isn't in charge so much as it is a really good storyteller convincing 'you' that you've done something yourself that you had no part in. Cut the interface between brain hemispheres and 'you' will still have the absolute self assurance that 'you' are the one in charge.