When I was a little girl, my father tried to tell me that Sherlock Holmes was not a real person. "But Daddy," I would sob, "if he's just a novelist's creation, then how could he possibly have known how many steps there were leading up to 221b Baker Street?"

Only a truly mindful person could remember a detail like that. And you too can learn to think like Holmes if you train your brain properly. But it won't be easy, as you will have to acquire a natural sceptism and inquisitiveness towards the world. Most of us have a tendency to make instant, crass judgments like that fool Watson.

Holmes's detractors often point out the supposed ignorance of Copernican theory he displays in A Study in Scarlet; but a close study of The Adventure of the Greek Interpreter proves beyond doubt that he had a keen understanding of the "obliquity of the ecliptic". What this shows is that Holmes could, when required, access everything he could possibly need to know from his brain attic. Try to think of a brain attic as a physical structure, a bit like having a concrete library attached to the top of your head with data in it. Now think of the difference between mine and yours. Mine is very large and yours is very small. Which is why you bought this book.

When stocking the brain attic, it is vital to make sure you do not fill it with clutter. Watson notices that "Miss Morstan is a singularly attractive woman" in The Sign of Four, while Holmes observes, "Really? I did not notice." Why is this? It is because Holmes has no Motivation to Remember (MTR) as he is completely out of his head on morphine.

In 1978, two psychologists did a fascinating experiment to show it was possible to get a statement of the bleeding obvious peer-reviewed in an academic journal, which would then be cited in every popular psychology book thereafter. Consider these two sentences. "Bastard, bastard, bastard, nice guy, bastard." "Nice guy, nice guy, nice guy, bastard, nice guy." If you were one of those who thought the person mentioned in the first sentence was likely to be more of a bastard than the guy in the second, then you are in good company – with the halfwit Watson. Only someone with an enormous brain attic could deduce the opposite because, as Holmes often told me, "Once you have eliminated the impossible, whatever remains, however improbable, must be the truth."

Do you remember when John Hector McFarlane arrives at Baker Street in The Adventure of the Norwood Builder? For Watson and Inspector Lestrade, his guilt is self-evident. Yet not to Holmes. Why is this? Because Holmes has the insight to know that if McFarlane had really killed Jonas Oldacre, then the story has ground to a halt on page one. Holmes can make those crucial mental leaps. Instead of going to Norwood, he goes to Blackheath. We all need to go to Blackheath sometimes.

We also have to recognise that we have limits. Even Holmes was not always infallible, but to those who observe that Sir Arthur Conan Doyle believed in fairies, I would say only this: just because you haven't seen one doesn't mean they don't exist.

You probably haven't heard of Ray Dalio. Ray is the CEO of one of America's largest hedge funds and one of the busiest people in the universe. And yet he takes time out to meditate before he goes to work. Why? Because it enables him to ruthlessly exploit the weaknesses in the banking system even better. Imagine now that you are Holmes and you are observing me, Maria, for the first time. What might you deduce? On second thoughts, let's not go there. Rather, let us consider the three-pipe problem. How do we recognise it? The answer is more simple than you may think. By smoking three pipes.

Digested read, digested: There are fairies at the bottom of my brain attic.