Here is a thought for munching on.

Assume the universe is simply an undirected naturalistic machine for a moment.  Eventually the human species will die out, and life on earth collectively will as well.  But while the story of life on our planet will have ended, the process of life may start again on another planet in one of the billions of galaxies out there.  Perhaps eventually the creatures on this other planet will even arrive at self-awareness.

The question is, if there will be cognizant organisms on this planet, is it possible I could be one of them?  Can I exist again? 

The immediate answer is not obvious.  On the one hand you can immediately think, as long as there are self-aware creatures there is no reason why necessarily you could not be one of them.  But on the other hand it seems that the definition of 'you' includes memories from the life you are currently living, and since those would not exist in the newly formed creatures, you could not possibly exist again. 

But I think that second part misses the essence of the question, since you could exist again while being completely unaware that you had existed before.  There are actually a few quite prevalent religions built around that fact. 

At the same time, if you try to think how you could possibly exist again, it does make you wonder what it would mean to exist again at all.  It seems in existing again you are referring to a relationship between two points, but that the points, since unaware of one another, hold no relation, and thus one cannot be the sequel to the other (since that would require a relationship between them). 

But it still seems that since there will be a creature that is self-aware on another planet, thinking to itself "I am me", that since someone has to be that entity thinking "I am me" it might as well be you.  Not you as in the you that is conscious of your life here, but you in the sense that you would know your self-awareness on that planet, and that is all.

But if you grant that, you must wonder, if it is possible that I existed before, and possible that I will exist again, why am I existing here instead of there?  There is no intelligible answer for that, except, of course, that you have to be existing somewhere, and at the present that place is here.  

Ever wonder if your mind is just like the universe, and your brain cells the philosophers trying to figure it out?  When you are thinking they are at their blackboards scribbling away, debating one another in lecture halls, and having angry shouting matches with one another next to the coffee table.  There are also sewer cells, the ones that wade through the slime and mire at the bottom of your mind in search of memories you are trying to recall. 

Ah, well, that was just fun to think about.  Perhaps you can ponder it as you go to sleep...and then after you have drifted into unconsciousness you will then wake up as someone else, and never even know.  Because after all, don't we wake up as slightly different people everyday?