What if's?
-Time Travel Possible?
Time Travel alone is a paradox in its self. You go back in time, and just being present alone, can change the out come of events. Of course if history is changed, then you shouldn't remember the events that did happen because they never were. If you on purposely went back in time to change something, you created another paradox. Because if you changed something then your reason for going back in time never happened, and if it didn't happen then the events should have not have been changed. Thus a paradox.
-Existence of Multiverse/Parallel Realities
Any thing you do, all choices and decisions, and events made, creates a alternate universe, were the choices, decisions, and events along with out comes are different. Say you flip a coin and it lands on "Heads" In another reality, it landed on "Tales."
-Events and Actions Cause Ripples Across time and reality.
Everything we do, and things that happen, creates a ripple across time and space. Some people and creatures are sensitive to these ripples, and thus, sometimes get a glimpse of what caused those ripples, this a premonition.
My Theory
[i]If Time travel were possible, and you went back in time to change a event, instead of changing your own realities future, i think you create a alternate reality instead. Were your original reality the events still happened, but when you changed the events it branched off another reality, were the events are different. Thus avoiding the paradox. And in some realities, perhaps a powerful event happens and creates ripples, and other realities, are effected by those ripples, were sensitive people get premonitions of what could happen to there reality that has happened in another.
Now say if you went back in time changed a event and now your living that reality of what you changed. Say you wanted to go back to your reality. Perhaps, the events you changed, created ripples, could those ripples be traced back to your original reality?
Any ways that's my theory. :p