Spoilers, of course: you’re not really supposed to consider the time-travel implications of the movie — Bruce Willis flat-out tells you not to! — but I was thinking about it for fun. The movie (which is great) is probably a paradox. Consider: a universe exists in which JGL closes his loop. Thus, Willis can’t kill the Rainmaker’s mother. The Rainmaker has no impetus to exist, right, much less kill off all the loops to possibly prevent his mom from getting shot? (Also, why not just send the loops back a few years later?) Or: does the Rainmaker rise to power solely in order to send back Willis in order to play out the narrative to save his mom? But by doing that, Willis no longer exists in his time, which, PARADOX. Another universe, the universe of the movie, exists in which Willis comes back and meets JGL without a hood, and the film plays out. The fix for this is that time travel exists in splintered-off alternate universes, in which each action in the past sets off a different timeline. Otherwise none of it makes sense. (That doesn’t make sense either, because then Future Bruce Willis is disconnected from Current JGL because they exist in different timelines, UNLESS TIME IS FLUID AND CAN ENCOMPASS ALL POSSIBLE EXISTENCES WITHIN A SINGULAR FRAME, aghhhh.)
The movie itself was terrific, Bruce Willis being Bruce Willis and also Joseph Gordon-Levitt being Bruce Willis, which was an unbelievable performance. It felt like a less impressionistic, gritty take on a mind-warping film like Inception or The Fountain, though the poetry of the love story(s) at the heart of those films and this one didn’t suffer at all for the lack of ambiguity. It was probably better for it.