I agree with you on the importance of rhetoric -- in the sense of really breaking down what people are saying. Though, I remember being taught some of that in school and I don't know if it stuck for most students. It's probably a disconnect between a subject learned for school and tests, and a subject that's really internalized. A lot of analyzing dusty old essays and historical arguments, not enough forceful application to one's own modern-day surroundings.
(And I think you're probably correct about the crossbow bit. The influence it had was in the manner of making arms more accessible -- hand a peasant a crossbow and all that. I suppose a different analogy would be World War 1 -- outdated charging tactics coming up against machine guns, though that's a case where defense had the upper hand over offense.)
Most things aren't going to stick for most people. I certainly only retain some small portion of every book I read. But I do retain some. There is value in exposure to ideas, I think, even if those ideas don't always take root.
Now, I think we've got a really idealized vision of Greece; Idealized by a whole chain of different powers who translated their work, so some of this could be complete bullshit, but from what we read, it sure sounds like they saw rhetoric and logic as the practical skills one needed to be a pundit, a talking head, a leader, or even a participating member of a democracy. So... if we were to give the modern equivalent, we'd teach people about modern rhetoric more than historical rhetoric. History does have a place, sure, but it's not a big one. (I... really, really enjoy history, but I think it has less value that advocates clam to understanding the future. )
There were hippies who talked a lot about how important the connotations of a particular word are. gah. I'm forgetting the author. But I read all my parent's stuff when I was a kid, and it made a real impression on me. For a long time, i would translate everything I heard into the same thing, only using words with negative connotations, with the idea of inoculating myself against such a thing, and because for whatever reason, the negative connotation felt more honest to me than the positive. Less manipulative.
But that's the sort of thing, I think, that people need to think about if they don't want to be sheep.
(And I think you're probably correct about the crossbow bit. The influence it had was in the manner of making arms more accessible -- hand a peasant a crossbow and all that. I suppose a different analogy would be World War 1 -- outdated charging tactics coming up against machine guns, though that's a case where defense had the upper hand over offense.)