It is a lamentable yet indisputable fact that a person’s degree of fame is very often in inverse proportion to how nicely they treat their fellow human beings. In fact, it seems that being in the public eye can be a licence to indulge your inner diva and generally behave like a toddler whose toys have been taken away by a particularly nasty nanny.

You will have heard of those riders for big-name rock bands where they require space for a 200-person entourage and a daily dry cleaning service. Or how about songstresses who insist on their assistants breaking in their high-heeled shoes for them, or demand that a life-size cutout of themselves be on prominent display at every venue they play.

To these I can add my own reminiscences of run-ins with famous faces: there’s the fashion designer who kept me waiting for almost an entire working day in a Paris hotel lobby. And I’ll never erase the memory of the TV chef who had a massive strop and stormed out just half an hour before he was due to be the star attraction of our painstakingly organised event.

But one night, after a boozy birthday bash, I was waiting for a cab home in Soho. This was in the pre-Uber days where you had to fritter away time in a squished cubby hole of a minicab firm, praying the omnipotent controller would call you next. I heard a fellow patron give his name as “McKellen” and idly looked up from my phone to see no less a personage than Sir Ian McKellen politely taking his place in the queue. Not for him the favoured rallying cry of those in the limelight: “Don’t you know who I am?”

Emboldened by my tipsy state, I ventured that classic late-night reveller’s request, the selfie, and he obliged in a most charming manner. This was despite the fact that, as I later cringingly recalled, I had addressed him as “Mr McKlellan” (put that down to my Scottish heritage) the whole time. The fact he was so delightfully self-effacing and down to earth with such a mischievous sense of humour restored my faith, if not in humanity, then at least in the art of being a celebrity.