Bill Gates used to think that sleep is lazy, and competed with colleagues to get as little rest as possible

• Bill Gates said that he used to think sleeping was lazy and unnecessary when he was younger. 
• The Microsoft co-founder competed with colleagues to sleep less than five or six hours a night. 
• Now he checks his daily sleep score to maintain good brain health as he gets older. 

Bill Gates admitted to skimping on sleep during his prime years at Microsoft because he believed it was lazy and "unnecessary."

The Microsoft co-founder spoke about Alzheimer's and maintaining brain health with Seth Rogan and Lauren Miller Rogan in the first episode of his new podcast Unconfuse Me. 

Gates, whose father died in 2020 after suffering from Alzheimer's disease, said he used to compete to sleep less with other colleagues at Microsoft. 

He said: "In my thirties and forties when there would be a conversation about sleep, it would be like: 'Oh I only sleep six hours, and the other guys like: 'No I only sleep five' and 'Well sometimes I don't sleep at all,' and I'd be like: 'Wow those guys are so good. I have to try harder because sleep is laziness and unnecessary.'" 

The billionaire has changed his tune about sleep since then and started tracking his daily "sleep score," he said. A sleep score is determined by the length and quality of your sleep and is something that can be tracked on an Apple Watch or a Fitbit, for example.

"Now what we know is that to maintain brain health, getting good sleep even back to teen years is super important," Gates said. "One of the most predictive factors of any dementia, including Alzheimer's, is whether you're getting good sleep," he added. 

Rogan chimed in on the conversation by comparing attitudes to sleeping with smoking in the 1950s and 1960s, saying: "When I was young the convention was 'you'll sleep when you're dead.'" 

He explained: "They used to think smoking is healthy. It is similar. That's where we are culturally – the things people think and understand about their own brains are where they were in the 1950s and 1960s. It's so far off from what actual science is reflective of." 

Gates has even taken tips from a book called "Why We Sleep" by neuroscientist and sleep expert Matthew Walker, which he reviewed in his blog "Gates Notes" in 2019. 

"I routinely pulled all-nighters when we had to deliver a piece of software," Gates wrote in the review. "Once or twice, I stayed up two nights in a row. I knew I wasn't as sharp when I was operating mostly on caffeine and adrenaline, but I was obsessed with my work, and I felt that sleeping a lot was lazy." 

The billionaire now aims to get between seven and eight hours of sleep a night.