The notion that inventors are anorak-wearing crackpots with glasses held together with Sellotape is beguiling but wrong.

I was on automatic pilot; ideas for gadgets kept coming, fed by a force of energy flowing through me and around me.

I'd work eighteen-hour stretches and fall asleep in my clothes. Then I'd wake up in the middle of the night, brew a pot of tea, and start work again. I was tired, but work had become pure enjoyment.

A good idea turns every cog in your mind, making you scared of bed in case the whole machine grinds to a halt.

Visionaries and dreamers have always been dusted with a little oddity.

Ideas for gadgets for the disabled were coming into my head so fast they seemed to be arriving from somewhere outside of me, beamed down by an unremitting force. I had little control over them, or their flow. I would wake up in the middle of the night. A blinding flash of an idea would rouse me from my bed and I'd rush down to my workshop to have a go at it before the inspiration dimmed.

Invention isn't some impenetrable brand of magic; anyone can have a go.