It has nothing to do with war itself, he already explained it and it's pretty easy to understand.
He just meant that people back in the days had more courage, a thicker skin and all that jazz. And actually yes, a lot of these young men were very eager to go to war despite the big dangers, some of them even managed to get engaged even tho they were below 18, because they "cheated" to get there.
And compare those kids with nowadays ones. Some of them are so "frail , so "sensitive" , so selfish and claiming they deserve everything but offering almost nothing in return...
So whoever gets bu**hu** by some words in a game just go learn life, get a decent (at least) C+ then (eventually) .. you can graduate magna cum laudae the growing up process