Think about it!!!

this will sound odd, but bear with the idea and possibility...

you know the felling when you are totally fine, then suddenly lose your energy?
How about deja vu?
or forget what you were doing, what you were getting, or where u were going and why?

Theory of time travel. Maybe not us per se', but a possibility of such.
A typical rule in (movies) time travel, when retrieving one from the past, bring them back before you went to get them, and they will not remember going forward through time.

I'm not entirely sure how that theory is supposed to work to be honest. I mean, to pick me up in this time, I would remember a time traveler saying "come with me", and the travel, the event to occur during the travel, and the return. Theoretically, my time line has not changed yet so I would remember all that had happened, becoming the new me within an alternate dimension, where as the old me from dimension 2 either stays or travels and not returns... Or simply just like a meld-like thing. I'm pretty sure two mes in the same time/dimension would cause a paradox and... well bad news. regardless, Memory would remain.

But basing this theory upon the theory that returning prior to time exit, would erase memory of said event...

The loss of energy. A future time traveler, picked you up, did something in the future (possibly past), and have returned, depleted of energy. Well, hell, you just ensured a historical event happened, or defended against a disaster...  You suddenly are tired from kicking ass whenever you just got back from. Badass. A time-traveling hero and you don't even know it.

Deja-vu.
Brief boosts into the future, you were picked up, and brought maybe moments, or days into the future, prevented a disaster, or event, brought back to the point before, do not remember fully, but the brief memory flashes back into your head. Sometimes its scary, and you think some bad shit is about to happen after a series of events, but doesn't. Leaves you on your toes. You stopped an event from happening. (or you can see in the future and prevent it on the spot)

forgot what you were doing, or why you were going to get from the other room?
you were picked up after your thought, and returned before you thought your thought.
Cool right? makes you think a little more about why it happens right?

How do we know this isn't a real thing? Maybe those of the future (distant future) have created time travel and patrol it to create the best possible future for the human race? Bringing minds from the past to assist in future issues? History repeats itself, and what better way to solve a problem now, than to learn from the past directly? Wouldn't you be curious of historical events, and how they truly happened? I know, if we were having a shortage on electricity, I would want to go to Franklin and Tesla for answers of how they would solve it.

Maybe, in the nearer future we have developed a technology that extends our lives past 100 years. after all, with modern advances in the medical field has shown a much longer life span today than earlier in history. Average span being 40 or 50, maybe 60 at most, and now we hear of 100th birthdays. Quite remarkable. Sooner than later we will be celebrating 150th birthdays, 200th birthdays... We could turn out to be considered a type of immortal in the future... Who knows right?

Time-traveling immortals? Time-lords? >.<
Wibbly-wobbly timey-wimey stuff?

Every one of us is a potential hero or villain in another time/dimension....
And we don't even know.