I am not instinctively observant. My natural disposition is probably akin to something like a pebble at the bottom of a stream, most things endlessly rushing over my head. Without making an effort, drastic changes in my immediate surroundings go totally unnoticed – a friend’s new car, a renovated shop on my road, mother’s haircuts – that sort of thing. Until an occasional lump of driftwood would come along and knock me over the head, I was very happy in my watery oblivion.

As a result, observant people always scared the bejesus out of me. I found the idea that they might turn their beady eye on to me as I gambolled about unwittingly positively alarming. The possibility that someone might be interested enough in you to make those judgements somehow triggers an Orwellian fear. Unplucked eyebrows, uncut hair, a hole in a jumper, broken shoes, a streaky fake tan, an uneven shave – these are the sort of things you leave unchecked, you console yourself with the thought ‘nobody will notice’, ‘people have better things to worry about’. But not everybody. Not all people. Those narrow eyed inquisitors see everything. Down to the last nose hair.

It’s bad enough to think they might notice the personal indiscretions you know are there, but assume others aren’t aware of. But what about the details even you can’t see? What will they deduce from those? The thought of it is enough to send you stir crazy.

It’s a bit like a super-power, perceptiveness. Take Sherlock Holmes – essentially, the Victorians’ favourite super hero. I’m pretty sure he even wears a cape. Or a capey-coat at least, so my analogy still stands. Holmes’ superior perceptive abilities are such that he can take advantage of the tiniest aesthetic betrayal. Probably not most accurately described as a modest chap, the man still never claimed to have magical powers or superhuman aptitudes. Only a ‘natural scepticism and inquisitiveness towards the world.’

We make deductions all the time – some are more obvious than others. I remember friends telling me once about the One Night Stand Game they used to play. Sitting in the front yard of a house on Brudenell Road on a Saturday morning, they would try to spot the unfortunate souls scampering home in last night’s get-up. Boys are harder to spot so you get bonus points.

Trying to figure people out is a natural instinct. For some more than others, yes –but if you make an effort, it’s surprising what you can correctly surmise. A little smear of green paint behind the ear of a friend in combination with a slightly croaky voice might lead you to question whether they went on an Otley Run the day before.

I’m loving this new found deduction technique, but I will offer a word of warning. Exercise with caution. Linear scars on the hands and small cuts along the knuckles could be an indicator of a person’s new foray into baking (oven burns and nicks from lemon zest grating) – but it could equally mean a penchant for cage fighting. So before you strike up a conversation about the Bake Off final on the bus home, you might want to be absolutely sure of the assumptions you make.