Quaid plays a repressed, anally retentive college professor at Carnegie Mellon. His wife died before the film starts but has an epileptic fit shortly after it starts, requiring him to me Sarah Jessica Parker (as his emergency room doctor) and call in his brother (Haden-Church) as chauffeur (you can't drive for 6 months after you have a fit).
We watch the effects of Jessica-Parker and Haden-Church on him and his equally anally repressed daughter (Page) for the rest of the film.
It was a depressing film, because Quaid isn't very nice for much of the film, and Page is thoroughly unpleasant for the entirety of the film. You can't watch 2 unlikeable people for a couple of hours without thinking "Why am I here" and I have to admit that that's what I spent most of my time thinking if I'm honest.
In addition, Page is supposed to fall in love with Haden-Church, but the age gap is far too big to make that believable. They had the chance to narrow the gap between the two. Haden-Church is described as Quaid's adoptive brother, so why not make him younger and that whole storyline more believable?
Finally, Page's part is described as a repeat of her role in Juno. I'm sorry but I don't see it. Maybe it's because she's playing a teenage Republican (which is a term that causes me to have a violent phobic reactions every time I think it), but I couldn't get past that idea to see the similarities.