The ancient philosophy of Stoicism – which teaches to be satisfied with what you have and includes practices like self-denial — has become a trend among Silicon Valley elites. But perhaps no one is more devoted than 42-year-old billionaire Jack Dorsey, CEO of Twitter and Square.

Dorsey tweets about his various Stoic endeavors, for which he is often derided: When he went on a 10-day meditation retreat in Myanmar for his birthday in 2018, he was blasted for being blind to the human rights atrocities occurring there. He's also been criticized for promoting questionable eating habits, like intermittent fasting.