‘This was survival, turning a disadvantage into something I could own’: Matt Lucas. Photograph: Ian Harrison/Camera Press

One of my earliest memories is of being three-and-a-half years old at nursery, watching the other little boys and girls skip out of the classroom and noting how the folds in the backs of their legs were unblemished. My own legs, like my arms and neck, were already riddled with scratches. I had been told repeatedly not to scratch – but if I didn’t scratch then there was nothing to do but wheeze. And, oh, how I wheezed. Dr David said I had eczema and asthma and hayfever, and gave me some special cream and a blue and white Ventolin inhaler, which I was to use every morning and every night and in between, if necessary.

From a young age I felt at odds with my body. This blotchy, dumpy vessel betrayed my boisterous, carefree spirit. I wanted to run, jump, climb – and I did, but within seconds I was bent double at the kerb, gasping for air.

And yet I remained funny, cheeky Matthew. Inquisitive, outgoing, playful, I had many friends, who I entertained with songs and jokes and silly voices aplenty. Even on the sidelines, while the others played football, I would pretend to be a TV commentator. My asthma and eczema were an inconvenience but they didn’t define me.

However, an event would soon occur that would shape my childhood.

In 1978, when I was four, Mum and Dad took my older brother Howard and me to Portugal on a family holiday. I was struck with wonder at the otherness of everything, and was easily distracted. I was always lagging a few steps behind, and my poor parents were constantly having to remind me not to wander off on my own.

One day, while we were walking along the street, I got separated from my family. I looked up and they were nowhere to be seen. I cast my eyes up and down and across the road. There were several people around and from a distance quite a lot of them looked like my mum and dad.