Kev, I ran into a guy once back in uni who was working full time and taking 18 hours in senior level computer science, yet still doing well in both. He obviously didn't have a life, not that I asked, but it can be done... somehow.
I know another guy who's a CIO and usually sleeps no more than 5 hours a day. The two probably run similar schedules? I've heard of some higher-ups that only run 3 hours.
(Just a random side-note guess, but they're either single or at high risk of divorce.

)
Morey 2020.
Q:How are they experts when they're always wrong?
A:Ask a stock market analyst or your financial advisor