TURNING POINT / Daytime: the great healer: Watching Crown Court, a flu-ridden schoolboy discovered television. Now he's on it. He's Mark Lawson

At the age of seven, I was entranced by the pictures of Neil Armstrong walking on the moon, and took to plodding round the garden in an astronaut outfit made from a bed sheet, but the miracle I saw in that case was lunar exploration, rather than the television transmission of it. It was 1974 before I woke up to the miracle of television, and Television Centre, London, replaced Cape Kennedy, Florida, as my spiritual home.

In 1974, most of the second form succumbed to a particularly snotty strain of flu. It knocked you out for at least a week. While recovering, I caught something else: the television bug. At that time, there was little daytime television - no future generation of viewers will have, as ours does, a test transmission card as one of its cultural references - and things didn't really get going until lunchtime. Then, after the news, ITV ran Crown Court, and BBC 1 screened Pebble Mill at One.

The first of these was a Granada drama, in which a trial was dramatised in three half-hour episodes each week, building up to the verdict and sentence, if any. The second was a lunchtime chat and music show, hosted live by Bob Langley, a dapper Cumbrian, and the late Donny Macleod, a squat Scot, from what was always described as 'the foyer of the BBC Centre in Birmingham'. Although, objectively, a reception area was moonlighting as a studio, the word 'foyer' was always spoken with a tremor of exoticism by the presenters. Subsequently, there was even a late-night evening spin-off, Saturday Night at the Mill, for which Langley wore black tie, the lights were dimmed and a piano was wheeled in.

It was while watching Crown Court and Pebble Mill at One, huddled in my dressing-gown with the fire on, that it happened. The shiver down my spine was nothing to do with the virus. After two episodes, I was desperate to know the verdict of the court case. And the Pebble Mill guest for that Friday was to be a writer (Frederick Forsyth, I think) who interested me.

This was years before the universality of video recorders. In those days, to say that you had to be sick to watch daytime television was a practical rather than a moral comment. On the Thursday evening, talking in a quiet, sore-throat sort of voice (though my immune system had pretty much finished its business), I tried out on my mother the old school logic that, once you had missed the first three days of the week, there was not much point in going back until Monday. She fell for it, and I learnt the fate of the accused and how Freddie became a bestseller.

Previously a bookish boy, from then on I would buy the Radio Times every week. Illness, or school holidays, still meant Crown Court and Pebble Mill, but my enthusiasm had become more general. I remember the sheer astonishment of watching, also in 1974, Paul Watson's Family, a cultural and technological breakthrough to match the moon landings, though this one was achieved by television, rather than reported by it. I have read many interesting essays since about how the Wilkins of Reading fairly rapidly ceased to be 'real people' - and how the series became a commentary on the effects of public exposure - but that was not how it felt to watch. It was raw, bleak, real.

On Tuesdays, after the news, I discovered Play for Today . . . Having looked up now the dates of my remembered favourites, it is amazing to find that, in a four-year period, it was possible to see work as varied as Trevor Griffiths' Through the Night (1975), Jack Rosenthal's Bar Mitzvah Boy (1976), Mike Leigh's Abigail's Party (1977), David Hare's Licking Hitler (1978) and Dennis Potter's Blue Remembered Hills (1979). The Play for Today series is frequently mis-represented today as dramatised minutes of Labour Party branch meetings, but, in this list, it is the range of subjects that impresses: breast cancer, Judaism, suburban snobbery, wartime propaganda, childhood. Film and studio, comedy and tragedy.

I understood perfectly well that, on literary and technical grounds, these pieces were far superior to Starsky and Hutch, Kojak, Ironside, Cannon and the other American cop shows. But I thought then, and still do, that television is about the coexistence of both kinds of work. The other images that come back to me from this incubation period are of comedies: Porridge, which began in 1974; Fawlty Towers and The Good Life (both 1975); and The Fall and Rise of Reginald Perrin (1976). But these don't really count. They are all around today, on BBC 1, UK Gold, or video. The television memories that really count are the ones that are hardest to get back.

The world of television was a distant one, although the 'man from British Telecom' who turns up on page 535 of Clive James's collected TV reviews explaining the 'underlying motive for the proposal to paint all the telephone booths yellow' is my dad. But I had plans to expand the family involvement in the medium: either as a TV critic, playwright or a presenter. To these ends, from the age of 14, I wrote private reviews in a diary upstairs, and secret screenplays in a notebook, and kept a careful note of the appearances of my favourite journalists - Clive James, Ian Wooldridge, Frank Keating - on television.

In 1977, the now-defunct London Evening News covered its reviewer's holiday by inviting readers to be 'our TV critic for a day'. My review of the Miss United Kingdom contest appeared in the issue of 6 September. A couple of months later, the BBC Television Script Unit sent back my would-be Play for Today called Lettuce to the Editor - in which an English teacher committed suicide after the madly ambitious editor of the school magazine exposed him as a homosexual - with a rejection slip, but a typed letter expressing the belief that I would one day write a screenable piece.

Nine years later, I had become a television critic, for this newspaper, and still write about the subject even in semi-retirement. Last year, I got a play on BBC 2, and am struggling with another. I present the odd programme; or an odd programme, as some critics have had it. Perhaps I got in too late, because it is fashionable now to lament the decline of British television, and there is some truth in this view. These days, a 12-year-old off school with flu who tuned in to the daytime output of, say, Carlton, would probably start feeling a great deal worse. But, even now, there are still programmes so good that they bring back my shivers: Between the Lines last year on BBC 1, the single drama Safe (a handsome grandson of Play for Today) on BBC 2, and the brilliant documentary series Watergate, currently running on Sunday nights.

And, watching or doing television, I remember 1974, when I caught flu, but also another bug, the serious after-effects of which have never really quite left me.

Mark Lawson writes in the 'Independent' on Tuesdays and presents BBC 2's 'Late Review' on Thursdays

(Photographs omitted)