This is a randomish thought.
I always read about how time travel to the past is widely accepted as impossible, simply for the grandfather paradox.
My question is this:
The grandfather paradox is only exploring the possibility of physically traveling through time, ie - you strap yourself into a machine and go back and hang out with yourself as a 9 year old. What about time travel in another sense?
More of a Goundhog's Day ideology would be that you travel back into time as yourself, ie - you return to your 9 year old self as your 9 year old self. Whether or not you are aware of your time travel in the scenario is irrelevant. The thought that you could change the past to affect the future to make your travel to this time impossible is what is said to make the idea of time travel impossible. I prefer to say it makes it illogical at best, as you will undoubtedly make the same mistakes (history repeats itself?)
So what if, you could travel into the past unaware of doing so upon your arrival? The idea that time is not constant and is experienced differently to each individual is very much fact, proved time and again by Einstein's theory of relativity. So, if you can use your mind to stop time (even if only to yourself), what is stopping the belief that you cannot use your brain to go backwards?
Whenever I have a deja vu, I think about this possibility. Am I merely reliving the same experiences again without an cognitive knowledge of it? Is that deja vu my brain's sudden recognition that I have in fact made these same mistakes before? Am I living again? Did the future me attempt to come back and correct the errors I believe I had made?