Was anyone else hoping for a nonlinear narrative?

When I saw the trailer for this movie, it emphasized the "start at the end, work backwards" idea, and that, along with the story of a man with memory sequencing problems involved in a plot, and the promise on the box of a twist, I was expecting a nonlinear narrative that played with expectations. I dunno, maybe I'm just too big a fan of Memento, but the straightforwardness and simplicity of the film really disappointed me. His mental difficulties don't even feature into the story that prominently. The only results we see are his hands shaking a couple times, some difficulty talking to people, and some alleged memory loss that doesn't amount to much. If he was just any dude who felt guilty about an accident, the story would be largely unchanged.

How could they put so much emphasis on rearranging the events of a story, and the hero's confusion over the order of things, and not make that a key aspect of the narrative? Just for the moment of tension when he remembers the gun in the bag?