I left school in the last year of the war, when I was 14, to become a plasterer’s apprentice — don’t ask me why. Then I worked at the Transport and General Workers’ Union in Smith Square and that was almost as bad. I remember running up the steps of Morden Tube to queue for a bus home one night, and it was as if a light bulb came on in my head. I thought: “I can’t go on doing this for the rest of my life.” I was only there for a year when I was taken ill. I’d had the symptoms for a while: tiredness, weight loss, a terrible cough, night sweats. My brother, Bert, came home on leave from the merchant navy and knew straight away that it was TB. There was a two-year waiting list for the sanatorium, but they took me within 10 days, which seemed odd. Bert told me later they’d given me six weeks to live.

The doctors were tough with me. The treatment was rest and I didn’t get out of bed for over a year. There was some absolutely horrific surgery, where they took away your ribs and pressed the lung down. As long as the lung didn’t work, the bacilli couldn’t live. We all feared it; I think it was the worst operation known to man. In the end I had an artificial pneumothorax instead. They pumped air between the thorax wall and lung and compressed it. It had the same effect.

We lived in two-bedded cubicles stretching down a long ward. The place was full of blokes who’d come straight from the war; as I was only just 17, I was a kind of mascot for a while. There was a weird system of promotion: “absolute bed rest” meant you were washed in bed, you couldn’t even get up to pee; “semi-absolute 1” meant you could use the lavatory in the morning; “SA 2” meant you could go twice a day; “bed” meant you could use the lavvy and put your clothes on to see the film show once a week. The word we dreaded most after our weekly examination was “same”. I still can’t bear to hear it. It meant no progress, you stayed where you were — for how long, nobody knew.

The idea was to build you up, then see how much you could take before you broke down. Some really fit bloke would be out of bed and walking rounds of the building, then he’d collapse and the TB would start again. When that happened, the mood of the whole sanatorium would go down. We had our sputum tested each week and if you threw a positive — and I always did — you’d be demoted and back to where you started. When you’re in that situation, you think there’s a conspiracy to keep you in. Other times I got the “black dog”, as Churchill called it, when I’d turn my head to the wall and wouldn’t talk to anyone.

The chap I shared with turned our cubicle into an engineering workshop, with a big RAF 1155 radio, and we’d listen to American comedy shows. A year after I arrived, Alan [Simpson] came from a hospital in Mitcham and we had the idea of writing a show to be broadcast within the san. We wrote four 15-minute shows called Have You Ever Wondered? before we dried up. Alan left the san soon after. I think he ate his way out and went back to work at the shipping office.

After nearly three years’ incarceration, the introduction of the antibiotic streptomycin saved me; six months later I was home. That was a shock, because after the san our house felt like a doll’s house. I still wasn’t allowed to work, so when Alan asked if I’d like to write for a church concert party, I didn’t have much to lose. Then we thought we’d get a professional opinion and we sent a sketch to the BBC. A letter came back and Alan came down my street waving it like Chamberlain out of the aeroplane at Munich. I swear, if nothing else had happened in our careers but the arrival of that letter, we’d have been happy.

We started writing for Derek Roy, then were asked to write six episodes of Our Show, which Tony Hancock was in. It was while we were writing Our Show we got the idea to do Hancock’s Half Hour, which we wrote for 10 years or so. I don’t know how we did it — we were writing over 40 shows a year. Then the BBC gave us a brief nobody had been given before or ever will be again: to write, direct and cast a 10-show series on any subject we liked. We called it Comedy Playhouse and it consisted of 10 little playlets.

We’d get the most terrible blocks. On Fridays, when we were meant to have everything in, we were sometimes still lying on the floor, not even started. One day I said to Alan: “What about doing a thing about two rag-and-bone men?” After eight hours’ silence, he said: “What did you say about the rag-and-bone men? Shall we start that?” And so we did.

Steptoe and Son in Murder at Oil Drum Lane, by Ray Galton and John Antrobus, is playing at the Comedy Theatre, London SW1, until April 22