I do have at least one acquaintance that watched it multiple times to understand it. In fact this acquaintance convinced me to go watch it, as I was actually curios about what's so hard to understand about it. And while watching it, I kept asking myself what's the big deal with it, as the plot unfolded itself pretty linearly.

So there is something about it that makes it hard to understand for some people, although my non-technical wife also had no problems with it.