Grant puts his Barbazon acting training to stellar use in this comedy about a do-nothing, thirty-something Londoner who discovers meaning in his life through his friendship with a young boy, Marcus (Nicholas Hoult). Fortunately for young Marcus, Will Freeman (Hugh Grant) is a useless, lifeless, womanizing lout with nothing to live for and nothing to lose, and not a priest. Thus, he represents an opportunity for young Marcus to change his life for the better.

Will becomes Marcus's faux father because he tries to pick up women at a single parenting class that includes Marcus's mother, Fiona (Toni Collette). Fiona cries a lot and tries to kill herself, which leaves Marcus in Will's care for no particular reason other than he's the only one around. At this point, the film has a very serious problem, which is this: Every movie like this demands that Will and Fiona fall in love. After all, Will is learning to appreciate maturity, and Marcus loves him, making him perfect father bait.

There's only one very serious flaw in this theory: Toni Collette looks like a normal human being, and thus by Hollywood dictate is not allowed to bed a romantic lead. Neither of Hugh Grant's expressions would be sufficient if he had to sleep with Toni Collette. Fortunately, the ever-industrious screenwriters/directors Paul and Chris ("American Pie") Weitz came up with a great solution. Fiona tells Will that she's not attracted to him, leaving him to pursue and bed the impossibly hot Rachel (Rachel Weisz), who's conveniently given a character name that she's not likely to forget.

Naturally, everything ends happily, with everyone's problems resolved in a fit of quick-fix screenwriting glee that suggests world peace could be solved in five minutes if only a Hollywood screenwriter could put history through a rewrite.