I had a very relaxed attitude towards potty-training as a child so that message made an impact.

When I was 2 1⁄2, my mother was tearing her hair out. My father, a British journalist based in the U.S., saw the ad in the magazine of an Illinois hospital.

An academic was pioneering a new method that he claimed would potty train any child in less than a day. Dad knew a good story when he saw one. And if it also meant the potty battles were over in our house, it was a win-win.

We boarded a plane to Illinois within the week. It was a snowy February day and I was wearing my favourite blue coat. My parents liked Dr Foxx straight away. He had a soft voice, long brown hair and a very 70s moustache. He took one look at me and reassured them that even I could be trained.

Remarkably when you look back now, Mum and Dad left me with Dr Foxx and his colleague Dr Azrin, agreeing to pick me up in 9 hours!

The new method involved a musical potty and lots of salty snacks that made me drink copious amounts of water. I also got to play with a doll and teach her how to sit on the potty. That appealed to my bossy side, and I liked the snacks. But I wasn’t falling for their tricks. A few hours in, I decided I’d had enough and grabbed my blue coat, ready to leave.

Knowing my parents weren’t returning for several hours, and that any success would be covered in one of Britain’s most-read newspapers, Dr Foxx persuaded me to stay. By pick-up time, the nappies were gone for good and I was in the promised big kid pants.

Dad got his story, and Dr Foxx and Dr Azrin went on to write a bestseller. Pictured on the back of that first edition, a little uneasy next to the musical potty, was me.