There’s the almost constant upheaval at Twitter where, after he bought the social media platform last year for $44 billion, he rolled out a raft of cuts from staff to offices to data centers.

That doesn’t take into account his other day job running Tesla—which comes with its fair share of challenges, including court cases. And then, of course, there’s SpaceX, the spacecraft manufacturer and satellite company he founded in 2002, which now partners with NASA.

So it’s no surprise he’s strung out a little more than most people.

In an impromptu interview with British broadcaster the BBC—which was shared on Twitter Spaces and reportedly had 3.3 million listeners at one point—the member of the so-called PayPal Mafia revealed he had a number or regrets about the Twitter takeover.

Musk, the second-richest man on the planet, has been vocal about the strain running three businesses has put on him. In February, he admitted he was “worried” about his mental well-being, and a search for a new CEO at Twitter has been hampered by finding someone “foolish” enough to take on the complex role.

In his sit-down with the BBC’s James Clayton, Musk revealed his long days—not all of which are spent at Twitter—frequently force him to sleep in the social media giant’s San Francisco headquarters.

He revealed: “I sometimes sleep in the office,” adding that he has a spot on a couch in a library on the building’s seventh floor “that nobody goes to.”

Musk is no stranger to sofa-surfing. Earlier this week, a fan on Twitter posted a photo of an empty-looking room with a mattress on the floor, claiming it was the bedroom of Musk.

The man worth $189.1 billion, according to Forbes, responded that the theory isn’t “totally wrong,” adding: “Slept on a friend’s couch last weekend.”

3 a.m. rule

At least when he is asleep he’s not getting himself into trouble, with Musk telling the BBC that perhaps he shouldn’t post on Twitter after 3 a.m.

Such antics online have got him into hot water with Tesla investors, after the boss was taken to court over posts that boosted and then sank the stock price of the EV manufacturer.

“Have I shot myself in the foot with tweets multiple times? Yes. I need bulletproof shoes at this point,” Musk said. “I think I should not tweet after 3 a.m—maybe 2 a.m.”

“Good” Twitter rules for users, he agreed, include not tweeting when angry or having had a drink.

“If you’re going to tweet something that maybe is controversial, save it as a draft and look at it the next day if you still want to tweet it,” he added. “That has been a good rule of thumb.

“There’s a bunch of things in my drafts that I’m glad I didn’t send.”

Twitter’s toll

In the BBC interview, Musk speaks candidly about how “painful” the process of taking on Twitter and transforming it has been, adding he “didn’t have a heart of stone.”

Such vulnerability isn’t unheard of from the CEO, who said in February the pressure he was under is a “pain he wouldn’t wish on anyone.”

Concern for Musk has been ramping up since November, when it was revealed his schedule consisted of waking up, working nonstop, then sleeping, seven days a week. This means his usual workweek of between 70 and 80 hours now sits at around 120—prompting a fan to tweet, “Please be safe and take care.”

Musk responded: “I’m worried about me, too.”

Then in January the CEO apologized during a trial for “squirming around” on the witness stand, ascribing it to “quite severe back pain” and difficulty sleeping the night before. 

As well as bad sleep on office sofas, Musk has also admitted his diet isn’t the best, as he eats a doughnut for breakfast every day.

Peter Diamandis, one of the founding partners of health care business Fountain Life, tweeted earlier this week that “sugar is poison.” 

Musk responded: “I eat a donut every morning. Still alive.”