It's a good thing.

Rating: 9/10 (28 May 2002)

** possible minor spoilers ahead **
This being my first Christopher Nolan film, I didn't know exactly what to expect with "Insomnia". "Memento" looked good enough, but a bit too arty to take in along with my film-watching buddy, i.e. my mother. "Insomnia", on the other hand, featured two actors good old Mom and I both like -- Al Pacino and Robin Williams -- so it was definitely something we could take in. And boy did we take it in!
Christopher Nolan seems to me to be a master of using visuals as a means of advancing the plot line, which is something I've rarely experienced before while watching a movie. This is a good thing. Al Pacino so masterfully played an L.A. detective afflicted with severe insomnia as well as something that weighs down his conscience. This is another good thing. Robin Williams is absolutely delicious as a truly evil and psychotic (as well as scarily intelligent) man, something I'm not used to seeing him portray either in movies or in interviews. This is yet another good thing. Hillary Swank does well what she is supposed to do, which is to fawn over Detective Dormer at the same time that she sharpens her own detective skills. This is yet *another* good thing. In fact, the only complaint I have has been raised before by another reviewer, which is the fact that you don't really realize why Will Dormer is so nervous about IA breathing down his neck until almost toward the end of the movie (in that brilliant scene with Rachel Clement, played by Maura "damn fine actress" Tierney).
My mother complained at the end of the movie that it went by too slowly for her, and indeed the main activity seems to be rooted in psychological play vs. pure action-driven adrenaline. If you're someone who likes thrillers to be filled with breathless chases down dark corridors and more turning heads than at a tennis match, this is quite possibly not for you. However, you would be missing an excellent film-going experience, as the movie is breathless for more intellectual reasons and everyone in the film gives their all, which rarely occurs with movies anymore.
In short: brilliant movie, fantastic mental gymnastics, loved the acting, a bit too slow-paced for certain people, revelation occurs too late (but better late than never!), desperately want to see it again sometime soon.