https://www.cnbc.com/2018/11/05/elon-musk-on-working-120-hours-a-week-youll-go-bonkers.html

For Elon Musk, the difference between a "manageable" work schedule and an "insane" one is somewhere between 80 and 120 hours of work per week.

"You're gonna go a little bonkers if you work 120 hours a week," Musk told Recode's Kara Swisher in an interview on Wednesday at Tesla's Palo Alto, California headquarters.