Born in Provo, Utah, Johnson was just 20 when he founded his first company Braintree — specialising in mobile and web payment systems for e-commerce companies — in 2007. By 2013, Braintree had been acquired by PayPal for $800 million, leaving him a very rich man. He got married, had three children and got divorced. He climbed mountains (Kilimanjaro). Ultimately, though, he spent much of the last decade overeating, drinking too much and dealing with a dark depression. He was determined to do something about it, so used his expertise to develop algorithms that would do a better job of defining how he would live. After much tweaking — tweaking that still continues — he arrived at a routine that involves getting up at 4.30am, eating all his meals before 11am and going to bed at 8.30pm. During the day he takes more than 100 pills, exercises and is constantly monitored by the team of doctors. His mantra, the slogan of his company, is, simply, “Don’t die”.