And little by little I learnt to manipulate the colours that I saw; to give myself that rosy glow, that gleam of something special. Or – when a certain discretion was required – the opposite: the comforting cloak of unimportance that allows me to pass unseen and unremembered.

It took me a little longer to recognize these things as magic. Like all children, reared on stories, I’d expected fireworks: magic wands and broomstick rides. The real magic of my mother’s books seemed so dull, so fustily academic, with its silly incantations and its pompous old men, that it hardly counted as magic at all.

But then, my mother had no magic. For all her study, for all her spells and candles and crystals and cards, I never saw her turn so much as a cantrip. Some people are like that; I saw it in her colours long before I told her so. Some people just don’t have what it takes to make a witch.

But my mother had the knowledge, if not the skill. She ran an occult bookshop in the suburbs of London, and all kinds of people came and went. High magicians, Odinists, Wiccans by the score, and the occasional would-be satanist (invariably acne-ridden, as if adolescence had never quite passed them by).

From her – from them – I finally learnt what I needed to know. My mother was certain that by allowing me access to all forms of occultism, I would eventually choose my own path. She herself was a follower of an obscure sect who believed dolphins to be the enlightened race, and who practised a kind of ‘earth magic’ which was as harmless as it was ineffective.

But everything has its uses, I found, and over the years, with excruciating slowness, I was able to pick out the crumbs of practical magic from the useless, ludicrous and outright fake. I found that most magic – when it’s there at all – is hidden beneath a suffocating drift of ritual, drama, fasting and time-consuming disciplines devised to give a sense of mystery to what is basically just a matter of finding what works. My mother loved the ritual – I just wanted the recipe book.

So I dabbled in runes, in cards, in crystals and pendulums and herbology. I steeped myself in the I Ching; cherry-picked the Golden Dawn; rejected Crowley (but for his Tarot pack, which is rather beautiful), pored earnestly over my Inner Goddess and laughed myself into convulsions over Liber Null and the Necronomicon.

But most fervently I studied Meso-American beliefs: those of the Maya, the Inca and, above all, the Aztec. For some reason these had always held a special appeal, and from them I learnt about sacrifice, and the duality of the gods, and the malice of the universe, and the language of colours, and the horror of death; and how the only way to survive in the world is to fight back as hard and as dirty as you can.