Depatterning is the breaking of associations between memories, concepts, ideas, behaviors and emotions (and possibly also psychosomatic or psychogenic moods, illnesses and pains). What this doesn't also say, and what is equally important, is the ability to repattern. This is plasticity. When one joins the military, falls in love, or joins a cult, what typically happens is depatterning through exhaustion, change of environment, increased stress (whether positive or negative), emotional or physical pain. This can make the rest of the world stop making sense for the person. Then, gradually, they develop new "sense" (connections between memories, concepts, emotions, attitudes and sensations). Quite literally, when a person comes "back" to a group he used to know after such experiences, not only is it likely that they will be suffering from the PTSD (post-traumatic stress disorder) condition, but they will likely have a different sense about them, and not "fit" the way they used to in that group.
IMO, PTSD is NOT actually a disorder, it's a signal to the person that something needs to be further addressed/reviewed. When people are mindful, they recognize these changes in themselves, accept the cue that something needs review, and look for the origin of their distress. In a society where we are thoroughly distracted and looking for an external authority to tell us whether we can reflect and how to reflect, it wouldn't surprise me to see higher incidence of people who seem to have PTSD at the drop of a hat. Plasticity needs to be encouraged (flexibility), developed and aided. IMO, this can be more important than higher education in determining happiness and wealth in the long term. Those who become thoroughly rigid and unwelcoming of new experiences ossify and become living anachronisms.