I wrote this on a typewriter, a 1926 L C Smith No 8. I suppose my technical history is no different from that of any other writer: from first love with pencils and pens, I moved to teenage experiments with a portable typewriter, a disastrous romance with a word processor that had trouble processing my words and then marriage to a computer that doesn’t understand me.

The computer changed my brain. Instead of writing sentences, I noted fragments. As I mashed them into the pictorial image of a paragraph, I pushed the rest forward like gravel before a glacier, then ground to a stop. My line of thought was equally pulverised. I was an addict, and internet-limiting software called Freedom only reminded me of my servitude. Now I am truly free and falling in love again.

No one saw me slip into Cambridge Typewriter in Arlington, Massachusetts. The owner, Tom Furrier, gently led me towards a Royal KMM. ‘David McCullough’s,’ he murmured. ‘It needs servicing.’ Involuntarily, I stroked it for luck. Tom understood: everyone does that, the first time.

Tom asked if I was looking for anything