You’d be surprised—the founder of a huge company like Amazon is likely to be an outlier in terms of how many details he actually can know. The more you learn about the biographies of exceptional leaders the more you realize that many of them actually had a hard, concrete understanding of what their organizations did that often exceeded that of the people who actually did the work on a day to day basis. But part of being a founder is that by the time the company outgrows what you can personally keep track of, you’ve cultivated a core of people around you whom you’ve thoroughly vetted as trustworthy.

Besides, the goal here is not that Bezos knows every detail; it’s that he knows enough of the details that a subordinate isn’t going to be able to bullshit him. And once he has trusted subordinates with a long history of not bullshitting him, he can offload some of the “understanding details” to them, so however difficult it was to try and bullshit Bezos, it’s going to be even harder to bullshit a team of Bezos and a trusted lieutenant.

And ultimately you can develop a skill or a technique for not being bullshitted even without knowing any of the relevant details ahead of time. Just as there are techniques to bullshitting a person, like handwaving and glossing over inconsistent or inconvenient details, there are also counter-techniques for not letting people bullshit you, like demanding all of the inconvenient details that people seem to be glossing over or trying to hide.

You don't have to know every detail. You just need a list of things to follow up on, and be somewhat decent at identifying when a subordinate is feeding you a line of bullshit