I have often wondered why some people passionately believe in conspiracy theories that really don’t stand up to serious inspection – or in many cases don’t stand up to the most cursory investigation. Take flat-earthers for example. They have to tie the facts in knots to justify their beliefs, postulating any number of lies and conspiracies in order to shoehorn their theory into a remotely sustainable argument.

You may well be aware of Occam’s razor, a strangely named scientific ‘law’ which states that the simplest explanation is usually the correct one. For conspiracy theorists of all kinds, however, the explanation can never be simple. Partly because if it were it would probably be true, but also I suspect because it would be no fun if it were.

I have concluded, you see, that most people who believe in improbable theories do so because they want to. Simple as that. I’m sure they wouldn’t acknowledge it, because that would undermine their argument, but I’ve never met anyone who espoused an unlikely theory who didn’t seem to enjoy it. And I have to admit, I’ve been tempted to get sucked in occasionally because I love a good story, and the conspiracy theories are usually far more interesting and better plotted than the rather pedestrian but disappointingly true explanations.

For most of us sceptics, the conspiracy theories look like hokum. But they are only an extreme example of something that almost all of us do from time to time – believe a thing because we want to, rather than because rational argument tells us it is true.

We want to believe social media is good for us, we want to believe the political party we support is better than the others, we want to believe our partner isn’t cheating on us, we want to believe there’s a market for our product, we want to believe the dog doesn’t fancy a walk today. It doesn’t matter how much evidence may be piled up against us, we remain blinkered to it, and only see the few crumbs of evidence that support our theory, the theory we want to believe in.

Listen, the thoughts and beliefs and ideas you most need to question in yourself are the ones that you like, the ones that you want to hold, the ones that serve your interests in some way.

As soon as you recognise that you are thinking what you want to think, that’s the signal that you need to scrutinise your beliefs and opinions extra thoroughly, and with double helpings of honesty and self-appraisal.