Alright so everyone has heard of the grand father paradox right?
If not here is how it goes (Well in my verison)...

A boy hates his grandfather so he goes back in time and kills him because he killed his grandfather,
the grandfather never had children and in return he was never born.
If he was never born then he could of never killed him in the first place. *Instant reset*,
(So he can't die because he wasn't born) then etc, you get the point.

There are so many shows that show people going back in time messing up their time line and shiz.
Well I think logically based on the time paradoxes and stuff. If you were to go back in the past it wouldn't change anything because it would've already happened in the main timeline.

Example: You go back in time and you see and communicate with your self.
Well then you would of remembered talking to yourself in the past already, etc.
I believe you can not fuck-up time because what you were going to do already was done.

What is Your Point of View About This
Do Share With Me... :)