Bryan Catanzaro stuck out at Nvidia. In the hive of engineering drones at the company’s Californian headquarters, he was the dreamer. His hair was long and he dressed like a jester in statement glasses and loud, tacky shirts. He was patient and kind, and he spoke in a soothing, gentle voice. He was the only Nvidia engineer I met who had a humanities degree.

In 2013, having worked at the company for a couple of years, Catanzaro was struggling. His big idea was to create a software library that would allow neural networks, intelligent computer systems modelled on the human brain, to train faster and more effectively. However, when he presented his prototype to Nvidia’s software team early that year, they panned it.