To me it feels like people that have been through THE SHIT face a point where they make a choice:

1. Wallow in defeat with the crushing knowledge that the world is unkind and unfair. Give up and angrily yell at others that haven't realized this yet. Lash out at those that are (at the moment) doing okay, because it is unfair that they are not also following choice #1.

or

2. Understand that things going well isn't the normal. Things going poorly is the normal, and for the brief periods of time when things are good, you celebrate them. You save your excess resources for the inevitable bad times. If you can you also help others that are in the bad times to ease their burden a bit. You prepare for things to go poorly again, because "poorly" is actual the normal.