I always thought it would be like this.



You can only live in the present, you can only directly effect the present. Every action you make rewrites the future. As soon as you go back in time, the present you were exisiting in becomes your future. While in the past, (your present), you kill your granddaddy. The future gets rewritten so that you were never born. This doesn't change the present though. As the future is being rewritten, the timeline doesn't follow you into the past again. It continues on in a straight line on it's merry way. You would continue existing the past (your present).

That's why I also believe that if you go back in time and talk to yourself, you won't suddenly get these memories of the conversation you had. By talking to him you only change the future. The remaining time between being talked to by your future self and actually going back in time you will have the memory, but as soon as you go back in time again, there will be 3 versions of your self. The present self, (the one that's supposed to be there), futureself #1, (Present self with no memories of being talked to and had gone back in time), and futureself #2 (present self with the memories of being talked to and had gone back in time).