After hitting me with the cancer diagnosis, the urologist offered me the choice of a longer life in exchange for my testosterone production. After some soul-searching, I agreed. I’ve been on testosterone-suppressing injections and tablets for exactly two years. The urologist has fulfilled his side of our Faustian pact. I’m still here. And everyone seems to agree that that’s the main thing.

At the same time as I was diagnosed, then agreed to have my testosterone reduced to castrate levels, I asked whether there would be any side effects apart from the obvious. And I’m almost certain that someone, perhaps a nurse, said that I might find crossword puzzles more difficult. In other words, the outer reaches of my vocabulary could become less accessible. This potential shrinkage worried me as much as the reduction of my crown jewels. Just how far would it go? Would my language faculty at some stage be reduced to ‘yes’, ‘no’, ‘quite nice’, ‘large one, landlord’ and ‘I’ve come to pick up my prescription’? I’ve worried about this but not researched it. I haven’t typed in ‘testosterone and vocabulary’, for example. In fact, it was only when I went to hear Cambridge Emeritus Professor of Neuroscience Joe Herbert give an hour-long talk to promote his book Testosterone: Sex, Power and the Will to Win that I once and for all nailed the fact that the word was ‘testosterone’ and not, as I imagined, ‘tostesterone’.

The talk took place in a medieval barn renovated in the 1930s according to Bauhaus principles, if you can imagine such a thing. A man with castrate levels of testosterone, naturally occurring, appeared on the stage of the converted medieval barn to introduce the speaker to the audience. Concluding with the information that Professor Herbert’s hobby is classic cars, he meekly withdrew and Professor Herbert stepped forward exuding testosterone from every pore. For a man of 78 he looked remarkably, even supernaturally, fit. His talk was most enlightening.

This simple, powerful, ancient molecule is responsible for reproduction, fertility, motivation, attractiveness (remove testosterone from a tropical fish and its gaudy colours disappear), competitiveness (up to and including wars), weapons (a baboon’s splendid incisors, for example), collaboration with other males (hunting, football hooliganism) and general risk-taking. The frontal lobes of males aren’t fully mature until their late 20s, which is possibly an evolutionary adaptation to ensure that young males take risks for longer. Risk-taking is essential for groups to gain territory and food and young males are always expendable. Isis, one could say, is a testosterone state. Professor Herbert thought that a world without testosterone would be ‘pretty quiet’.

Men’s testosterone levels are on average ten times higher than women’s. Testosterone increases optimism. It is not for nothing that traders on the floors of financial exchanges are almost always young males. A study has shown a connection between a financial trader’s fluctuating testosterone levels and his daily profit. And yes, in general men are indeed better at spacial awareness.

As I listened to Professor Herbert, I wondered whether the antithesis of this simple, ancient, powerful hormone testosterone wasn’t political correctness. And that political correctness (plus the porn industry) is in effect simply the testosterone regulator of an over-dense population. And the other thought that occurred to me was that if the Twitter mob ever got wind of this, here was another science professor about to be strung up by the balls. Indeed it was not unfeasible that any moment the smartphone in Professor Herbert’s trouser pocket would start vibrating like mad, pregnant with the news that he was out of a job.

He enlivened his talk with photographs projected on to a screen: a grimacing baboon, a Porsche Carrera, a tropical fish, and Didier Drogba shielding the ball in the opposition penalty area with Frank Lampard watching anxiously. A quick quiz question. Could anyone identify this football team in blue, he wondered? Receiving zero response from the low-level-testosterone audience, he turned to the castrate-testosterone-level male who had introduced him. ‘Any idea?’ said the prof. A defensive, arm-folded shrug suggested that he not only had no idea, but that the game of football itself was rather beneath his notice.

There was no time for questions after the talk, unfortunately. So I bought his book (£16.99) at the book sales counter and queued for a signature. When finally I was face to face with Professor Herbert, I gave him the book to sign and said I had a question for him. Was it true, I said, that the chemically castrated, to add insult to injury, are useless at crosswords. Pausing his biro, he looked up from the title page of his A-Z of testosterone and answered with an eight-letter word; clue: the fount of all knowledge.

‘Bollocks,’ he said.