Unfortunately, such things do not exist. The brain is magnificent and unique. Even if one was to hit their head and suffer from "memory loss", somewhere inside the brain, that memory is still there (long-term memory). Magic does not break science (this is what I believe, but you may try to prove me wrong). And even if it's possible, memories should not be tossed aside, for it is our experiences that create won we are. We must feel pain, fallen into injury in order to learn. That is the unfortunate truth.