The Tickle Your Own Brain Refuses To Feel

Get a friend to tickle you and you'll howl. Do the exact same motion yourself and... nothing. Not even close. Your nervous system is running a hidden calculation every single second, and it quietly kills one specific sensation before it ever reaches you. What is it protecting you from feeling, and why does it only work on yourself. Stick around, because the answer says something strange about how much of "you" is actually just prediction.