Working with TBI (traumatic brain injured) people has allowed me to see this. There are lots of vets coming home with undiagnosed, and untreated head trauma, most of the time its from being near an IED when I goes off.
Sadly, they usually aren't the ones to realize that they are a little off(or a complete retard/different person) until they get home, at which point their loved ones who knew them prior to the head injury point out the above fact.
