Mental time travel is where your mind travels back in time instead of your body. You keep all your thoughts and memories from the present, but your body is your younger self in the past, and you can't travel to any time before you existed. Apparently, mental time travel isn't all that common an idea in real life, but it shows up a lot in fiction. I was wondering if anyone here had ever thought of this or knows how to do it. If so, please post.