This movie is often touted as being incomprehensible, at which point someone usually drags out the timeline (unrealitymag.com/wp-content/uploads/2011/09/primer-chart.jpg). And if you're watching this as solely a time travel movie, you might want the chart -- it's certainly more complicated than Back to the Future's "line with a branch" chalkboard diagram.

However, this movie is as much a character study as a brilliant piece of scifi, and appreciating that doesn't require a chart.