Another of my observations is that everyone needs to learn this stuff on the job. There's no way to teach this stuff except by direct experience. 

Then, people are either born wired to deal with it, or they are not. Some people are natural stoics, some people are born histrionics. 

I'll give you an example from research:

Hospitals find that the average ICU nurse lasts only two+ years on the job in the ICU. ICU nurses receive a lot of training, and a hospital typically has a hiring bonus and training costs invested in ICU nurses. Yet, they cannot seem to retain them.

So hospitals invested a bunch more money in "resilience training" - trying to train the nurses to be able to handle what they see in ICU's[*]. The studies done on the results of this found that resilience training is statistically undetectable in the rate at which nurses leave the ICU area. One study, however, found that there is a cohort of nurses who last, on average, at least eight years, and have some nurses who were in an ICU for over 15 years. What was the variable that they found to be statistically relevant in predicting whether a nurse would last in the ICU job?

Whether the nurse had two or more children, with three children being a strong predictor of lasting more than eight years, and if the nurse had two more male children, then they really lasted a long time in the job. Well, you cannot ask people "how many children do you have?" in an interview - that's a federally prohibited question. So much for all the efforts at "resilience training."

[*] lots of patients die in the ICU, and as a result, there is a lot of drama from families in the ICU. There are nurses I know who swear that, no matter how much they could be paid, they will never work in an ICU ever again.