I once read a commentary about human resilience and boredom. One of the points the author made is that mental illness was pretty much non-existent in London when it was being bombed by the Germans in WW2.
This doesn’t surprise me. I suspect that real, tangible danger is less mentally damaging than the imaginary dangers of modern life.
When you live on the edge, life is exhilarating. I have been fortunate to have lived through a bunch of "exhilarating" experiences.
That's why I love that movie, "The Edge" with Anthony Hopkins. After you've been through something like that (or a bombing in London), you're not the same person.
It's liberating.