Here's what I don't get about this trope in classic literature: Why is stealing someone's coat such a serious thing in a lot of classic books?

I mean taking your friend's coat is still an asshole thing to do, but you could always get a new one. No one is going to die from this. Not a life or death thing. Why the big deal?

Why do classic literature characters seem to overreact to someone stealing their coat? I've read even some character that would be in tears, and say to their friend who stole their coat," how could you do this to me, my dear friend?" Something along those lines.

I mean... calm down. Yes, your friend was an asshole for doing that, but you're making a mountain out of a molehill. Just get him to say sorry and buy a new one for you, and water under the bridge. They make it out to be some grave wrongdoing,but it's really not.