And those paragraphs will contain the word "war" many times.
Also, wars are kind of interesting. A good guy (us) and bad guy (them) is a fail-proof way to make a story mildly interesting.
I guess there's other lessons we should learn from history (as opposed to trial and error, or observation). Political systems are a good one - there's things we could learn from the Greeks which could apply today (like sortition, as a way to stop career politicians getting too powerful, but still giving the decision makers enough power that they have an incentive to properly study the issue). We could also learn about dealing with natural disasters, resource exploitation, and the history of moral panics.
And the good guys always win! (or the winners are the ones who are left to call themselves the good guys)
And this makes sense: most soldiers spend most of their time waiting around for battles or marching from one battle to the next. The actual battles themselves take up very little of their time (even if they're extremely stressful).
The stories of those that lived through wars as civilians (the vast majority of people) of course never talk about technology and tactics as they had nothing to do with them.