That kind of thinking can lead to a culture where people don't want to take vacation because it means they are less "busy" than others and by implication, less important.

It becomes a badge of honor to let unused vacation expire at the end of the year because you just didn't have time to take it.

I've seen it more than once.

Facebook has hundreds of mid and upper level managers. I doubt that Zuckerberg is that involved in the intricacies of everything. After all, that's why you hire and delegate to managers in the first place.

What this really means is, no acquisitions for Facebook once leave starts (except maybe the ones he's already greenlit). At the CEO level, you focus on direction, strategy, and top-level execution of said direction and strategy. You're not designing and doing grunt work. If anyone can step back from a large corporation and watch things keep on humming along, it's the CEO.

Hopefully he can delegate and has trust in this. A lot of managers, even senior, can't. It is a skill.