Your brain knows what you’re about to do, so it cancels the surprise.
Tickling works because your brain is caught off guard by an unexpected touch.
When you move your hand, your brain already knows what will happen next.
The brain reduces the tickle feeling because it expects the touch.
Without surprise, the brain doesn’t react strongly to the touch.
Another person’s touch is unpredictable, so your brain can’t prepare for it.
It filters out sensations caused by yourself so you can focus on the outside world.
