I think Altman said in Lex F. podcast that he works 8 hours, 4 first one being the most productive ones and he doesn't believe CEO claiming they work 16 hours a day. Weird contrast to what described in the article. This confirms my theory that there are two types of people in startups: founders and everybody else, the former are there to potentially make a lot of money, and the later are there to learn and leave.