What frustrated me was the thought that with three thousand years of history someone in China, some monk in a monastery halfway up a mountain, must have developed a magic kata, a physical expression of formae. Or at least have got close enough to explain all those legendary swordsmen and their inexplicable desire to roost on the tops of bamboo trees.

If you ask any police officer what the worst part of the job is, they will always say breaking bad news to relatives, but this is not the truth. The worst part is staying in the room after you've broken the news, so that you're forced to be there when someone's life disintegrates around them. Some people say it doesn't bother them - such people are not to be trusted.

The Metropolitan Police Service is still, despite what people think, a working-class organisation and as such rejects totally the notion of an officer class. That is why every newly minted constable, regardless of their educational background, has to spend a two-year probationary period as an ordinary plod on the streets. This is because nothing builds character like being abused, spat at and vomited by members of the public.

Not being invited in is one of the boxes on the “suspicious behavior” bingo form that every copper carries around in their head along with “stupidly overpowerful dog” and being too quick to supply an alibi. Fill all the boxes and you too could win an all-­expenses-paid visit to your local police station.

The first rule about a black woman’s hair is you don’t talk about a black woman’s hair. And the second rule is you don’t ever touch a black woman’s hair without getting written permission first.

It's a sad fact of modern life that if you drive long enough, sooner or later you must leave London behind.

My dad once told me that the secret to a happy life was never to start something with a girl unless you were willing to follow wherever it led. It's the best piece of advice he has ever given me, and probably the reason I was born.