But don't for a minute assume O'Nolan would have similarly shouted down anyone taking him seriously. I gathered, from this documentary, that O'Nolan was a man simultaneously convinced of his genius and in thrall to recognition. He would have regarded praise as his due, yet he needed the approval of his peers as sustenance. Approval, narrator Brendan Gleeson told us, came early in his career, and from such luminaries as Joyce, Beckett and Graham Greene, enthusiastic reviewers of At Swim-Two-Birds, which O'Nolan wrote in his 20s.

That was about the height of it while he was alive, but here, 40 years after his death, we had declarations again of his timeless brilliance.

It was a story of sadness all told . . . of rejection and despondency and complacency and, finally, talent gone to seed and depression and alcoholism . . . but the sadness never overwhelmed, because it was also a story of great humour and irreverence. Contributors appeared genuinely tickled at the memory of O'Nolan, or . . . in the case of those who never knew him . . . tickled at his invocation. A slight bum note was struck, however, with the consciously higgledypiggledy structure which, far from honouring the postmodern shape of O'Nolan's work, seemed imposed.

In so far as any 60-minute programme could hope to peg the elusive Brian O'Nolan . . . his own brother Micheal stated that no one could know him . . . this was as decent a profile as you could probably wish for (that is to say, inevitably condensed and slightly unsatisfying). The least going for it was that it successfully conveyed what wonderfully loveable books At Swim-Two-Birds and The Third Policeman are, that it captured for posterity the thoughts of the last remaining people who knew Brian O'Nolan, and that it put a face and voice to the greatest enigma of the Irish literary pantheon.

Sadly, that face and voice came in a clip from a pitiful 1964 television interview with a young Tim Pat Coogan. O'Nolan, embittered, spiky, sozzled and nearing the end of his life, bragged that he had a masterpiece left in him, dismissed his work to that point as "trash", and railed against illiteracy amongst his peers.

Coogan said it was a pity that this is the only recorded interview of O'Nolan, because it was a bad record. Hopefully that interview will only ever surface in programmes like this, giving it context and reminding us of uncommon genius.

Only a select few in any generation will know what it's like to be a genius, but new crime series Numb3rs (Monday, Channel 6) actually puts you in the head of one, for a little while at least. At certain times in the show, you see what maths whiz and unofficial FBI recruit Charlie Eppes sees.

Where you and I would see random patterns and mundane compositions, Charlie sees twirling square root signs and algebraic symbols, the same sort of numerical scree you'd imagine fills the peripheral vision of android assassins and German footballers. When he's not seeing the latent geometry of our everyday world, Charlie spends a lot of time in a choppily-edited frenzy in front of a blackboard.

He's doing it all partly out of a love for the numbers, partly to give his brother, a more straight-up FBI agent, a dig-out.

It's all very akin to CSI and Without a Trace. I can't really get worked up about those sorts of programmes. There are rarely suspects to keep you guessing, only a bad guy who appears right at the end. In Numb3rs, the killer got blown to oblivion after it had only just about been established . . .

on very, very dicky evidence it seemed to me . . . that he was the perpetrator.

It reminded me of that scene in The Naked Gun when policeman Frank Drebin was being presented with an award for "his 100th shooting of a drug dealer".

"Actually, " the modest Drebin pipes up, "the last three I accidentally backed over with my car. And by chance they just happened to be drug dealers."

Scarily, Numb3rs doesn't appear to be playing it for laughs.

But then America can be a very scary place, as Morgan Spurlock demonstrated on Morgan Spurlock's 30 Days (Monday, Channel 4). You might remember Spurlock from the docu-film Supersize Me, in which he proved that eating McDonalds food for a month will make you poo suet.

This time, himself and his wife Alex tried to see what it was like living on the US minimum wage for 30 days. They chose one of America's poorest cities, Columbus, Ohio, as their test site.

The first week or so, they were bucked up with the spirit of adventure, but then lack of money, and . . . crucially, when Spurlock damaged his wrist . . . lack of health insurance began to bite. The lesson was that if you're poor in America, and especially if you're poor and sick, you're thrown to the wolves. The Spurlocks went to pieces.

It was easy to be cynical. You wanted to shake them up and say, 'Look dudes, only eight days to go before you can concentrate on making thousands of dollars from syndicating this show.' But you felt it was all coming from a good place, that they had the best of intentions, that the insight was everything. At least they're not stand-up comedians, put it that way.