I think the statement I made was that almost all veterans will experience some kind of a challenge, because for many during transition almost everything can be changing at once. That could be military culture, housing, where they're living, social networks, source of income, and they may have physical and mental health conditions upon release. Therefore, by definition, there's vulnerability built into that period of change.
Some veterans will encounter special problems during that period. Some of those can come from really the way they experience the change themselves, for example, if they hadn't planned in advance about what it would be like to take the uniform off. A number of veterans I've run into will talk about this issue, that they've lost their sense of purpose. In a sense, they've lost their sense of self. Some veterans are angry when they leave. They had planned on spending their whole career in the military, and their career was cut short unexpectedly, so sometimes veterans will have a feeling of anger or even betrayal upon leaving the forces.
There are so many factors coming together in transition all at one time that it has to be done well, especially for people who can get stuck, or they can get onto this trajectory that can lead to serious outcomes that perhaps exacerbate mental health problems, or even things like suicide.
I hope that's helpful.