Yeah I guess that's fair. I guess my point is that when you meet that expert, your contribution to the conversation is typically going to be blurting out <pharoah-name> and <pyramid-name> because thats all you remember from that one read, then more or less passive listening until you change the subject. But probably that's more or less enough depending on your goals. What happens when your expert responds, "No I didn't work on that, I did <x>"? Yeah you can try to engage them, but at that point you may have no more context than before you read the executive-summary.

I would argue that having a more bottom-up learning would help you get more from that next conversation by having a lot more context and opinion then the handful of key-phrases you've managed to recall months/years after. That way, the next time you have access to an expert, you can are building on that knowledge, rather than growing a list relevant of words. To be blunt, its the difference between being a student and a tourist.