Primer

Primer is an extremely low budget independent movie filmed by a skeleton crew and starring the director's friends and family. It is also one of the most intriguing looks at time travel I've ever seen on film. It's pretty much impossible to really understand the full extent of what's going on in just one viewing, and it was years before anyone actually found a complete solution that the filmmakers confirmed. The beauty of the film is that the important parts of the story are comprehensible without full knowledge of the time travel intricacies, which are mostly there just for the enjoyment of repeat viewers.

I thought I knew what was going on until the last 20 minutes (the movie only lasts about 75), at which point the complexity of the machinations ballooned and I lost the thread. It wasn't until reading about the movie later that I found out I never really had the thread to begin with. And now that I've seen so much more of the full scope but still don't really understand how it fits together, I have an inkling to watch the movie again today. Do you know how often that happens? I mean, how often does that happen to you? I think there's plenty of enjoyment to be taken from movies like Back to the Future that play fast and loose with the laws of time to create an exciting adventure, but I've never seen something like Primer, that takes the theoretical science behind it and really makes something deceptively simple but truly intricate and nearly endlessly rewatchable. Any fan of serious science fiction should see it.