I found I loved seeing patients by myself as much as I'd hated the neuropathology and neurochemistry. I found the patients extraordinarily interesting and moving. And I'd originally thought, you know, what can be duller than migraine, a headache, but it was an enormously rich... and, indeed, I still feel this love more than 40 years later going... I've gone back to the subject a little bit in my present book.

But none of the published papers satisfied me, and then one weekend I went to the rare book section of our library and I took out a book on megrim, as it was called in the 19th century, a book by a man called Edward Liveing, which was written in the 1860s, published in 1873. Weekends were my drug time, in particular my amphetamine time; I was heavily and dangerously into amphetamine then. I think I'm lucky to be alive because, you know, I would throw down 100 tablets, or whatever, and that would triple one's pulse, I'd run a pulse of 200 for the weekend – double one's blood pressure.

But I would be in a state of... in a sort of ecstatic orgasmic state, and... which I would devote to sexual fantasy. I had to go in for sexual fantasy a lot, because there wasn't much in the way of sexual reality. But that weekend, instead of my usual fantasy, I opened this book on megrim, and with a sort of catatonic concentration you can become very emotionless sometimes on amphetamine, I read this huge book and the feeling of drug ecstasy somehow flowed into the book. I... I thought it was perhaps the most interesting book I'd ever read. I started to think that this was mid-Victorian medicine and science and... at its best, along with rather beautiful writing, and, also social conscience that made me think of Mayhew's books on London's Labour and [the] London's Poor. And... and as I was reading this book, I got a sort of hallucination or vision, an absurd one, of migraine shining like a star, or possibly an archipelago of stars in the neurological heavens. I can't explain this or make sense of it now, but I also got a strong feeling that a book... another book like that should have been written.

I thought: now it's the 1960s, who will be the Liveing of our time? And... a dozen names came disingenuously to mind followed by a very loud internal voice which said, 'You silly bugger, you're the man'. And previously, whenever I'd taken a huge dose of amphetamine, I'd always sort of become manic and ecstatic, I would come down feeling terrible and with a sense of great folly and with nothing to show for the experience. This time when I came down the feeling persisted. I xeroxed Liveing's book, and I started on a book of my own, and in a way that launched me.

I think one of my reasons for turning to amphetamine was that I... I felt that mental life and creative life had... had ceased, in fact had ceased for 20 years. But then writing Migraine things started up again, and basically apart from a little pot once in a while, sort of the drug, the big drugs, the heavy drugs have... are long in the past. But I do feel... I think something like this would have happened anyhow, but I think it was more dramatic and acute with the amphetamine.