This film has evolved to join the 'little comedies that could' subgenre, charging up the charts and hoovering up truckloads of box office revenue after enjoying spectacular word of mouth.

The really funny aspect is that you've seen this boys-will-be-boys theme a million times, from Porky's onward. All any subsequent effort can offer is jokes we haven't heard before. Kooky characters, outlandish situations, implausible plotting - we've seen it all.

Four friends go to Vegas for a bucks weekend, and after drinking a toast on the hotel roof, they wake up the next day with no idea what's gone or why there's a) a white tiger in the bathroom, b) a missing tooth, c) a missing bridegroom and d) a baby.

Desperately trying to retrace their steps so they can find the groom in time for the wedding, they'll also a) be married to a ditzy hooker (Graham) b) steal a police car and c) come up against a Chinese gang lord who's a little less scary than he thinks he is.

Such bullet-pointing isn't just me. I got the feeling they spent the first day of scripting coming up with the craziest characters, scenarios and happenstance he could and then spent the next two months writing a plot around it. Jokes peppered liberally throughout and successful casting did the rest (rising star Cooper a likeable and popular hero and boorish Galifianakis the latest 'weird sidekick guy' in a long line of them), and the rest is $450m history.