In a nutshell, here's what happens: Jean-Claude Van Damme is a cop who moniters people who travel thru time. No biggie. In the beginning, his wife hets killed right before she can tell him she's pregnant. 10 years pass. Some corrupt politician is using time travel to get money to work on his campaign, which is illegal, blah blah blah... The politician, it turns out, is responsible for the death of the wife. In the end, Van Damme wins by kicking people. And now, the fun parts:
One of the important parts of time travel is that you can't travel into the future because it hasn't happened yet. However, if you're in the past, you can return to the present. But if you're in the past, the past becomes the present, and the present becomes the future, and everything you do will have an impact, thus making the future different. That means that the altered future hasn't happened yet.
Another thing they keep telling you is that the same matter cannot occupy the same space at the same time. Ok, I can deal with that. The problem is that they seem to think that if a person touches a past (or future) version of himself, they're occupying the same space. NO! They're not! They're just really close. Anyway, it doesn't matter because over the course of ten years, the matter in a person's body will change. But I'll let that one slide, I guess, for the purpose of storytelling. Now, at the end of the movie, the house is filled with C-4 and is going to blow up soon. The reason for this is that the politician went into the past with his henchmen and planted it in the house. Jean-Claude kills the politician by throwing the younger politician into the older politician, killing both. Since the younger politician is killed, the older one can't exist, which means he never would have gone into the past and, pay attention because this is important, the house would never have been blown up. Jean-Claude and his wife narrowly escape the explosion nonetheless, changing the future.
When Jean-Claude gets back to his own time, he asks his boss something about the politician, and the boss looks at him like he's crazy because the future has been changed and, of course, no one else noticed it. That's to be expected, but you'd think that these people who work with time travel every single day would come to expect their agents returning and talking about things they changed (or kept from changing). So, anyway, Jean-Claude goe fixed the future, he raised this kid and spent many years with him, but for some reason has no recollection of it. Now, if altering the course of time will alter a person (as is illustrated when young bad guy gets cut and old bad guy suddenly gets a scar), wouldn't his memories alter?