Film buff Tim Knatchbull has become a hardcore obsessive

'Well, there's a retrospective of that Chinese director Hoo Hee at the NFT," Tim instructs his friend Max, one hand clutching the phone to his ear, the other riffling through a newspaper film guide. "I think they're starting with Oh How the Pistons of the Locomotives Hymn the Struggles of the Workers and then going on to Szechuan Confidential. Or there's the new one by that Egyptian chap El-Alamein at the Plaza. It's meant to be terribly good." It is at this point, alas, that Max suddenly remembers his mother is in town, whereupon the prospect of a jolly evening out withers and dies.

It is not quite certain when Tim, an unmarried solicitor in his early thirties, stopped being the kind of person who enjoys going to the cinema twice a week and metamorphosed into a hardcore obsessive. Nonetheless, friends were quick to mark the change in his habits and conversation. Gone was the man who would innocently enquire, as the closing credits rolled, "No way! Was that really Robert de Niro?" and in his stead emerged a cinematic completist who turned out not only to have sat twice through Paul Verhoeven's Flesh+Blood but also to own a highly obscure director's cut version nearly twice the original length.

There are, of course, a number of different varieties of film buff. There is the one who mugs up on biographical detail and can attribute an actress's poor performance to her being between divorces. There is the one who dilates on camera angles and cinematography ("That's another thing about Harbourmeister – always has a good lighting man"). And then there is Tim's type, the specialist in foreign marginalia, capable of observing, with no irony whatsoever, that there is some really good stuff coming out of Guatemala at the moment or that the unavailability of so many of those Tamil vampire movies on DVD is a scandal.

The general conclusion among Tim's friends is that this new hobby is a mixed blessing. On the one hand, it has replaced his former shyness with a ready-made fund of conversation. On the other, no one dare say anything about cinema in general, or the latest release in particular, without risking the prospect of instant, pedantic correction ("I think you'll find that's the third time he's worked with Woody Allen"). As to why so many of Tim's cinema visits should take place unaccompanied – well, who can say?