One of my Grandfathers was in WW1. He fought on the western front, was captured towards the end of the war in the big German push of 1918, spent several months in a POW camp and then came home.
He very rarely spoke about the war, and almost never about his experiences at the front, and if he did it was in some humorous and non-personal way. He never bought German cars and never went abroad and lived a very happy life until he died aged 87. He had successfuly BOXED OFF the nasty experiences of the war. He essentially followed a technique that neuro-plasticity studies commend: the less you think about something the fewer connections are grown in the brain linking to that thing and the less important it becomes.
This may look like denial but it is different. Denial is when you focus on something by denying it. The man who tells the world he hates money but spends all his time talking about how bad money is. What we give our attention to we love, in the sense we are actively building connections to it in our ever changing and growing brains.
But boxing off, compartmentalising, is simply telling yourself not to think about a thing. As soon as you catch yourself you change the mental subject so to speak. And you don't encourage that thinking. You don't go abroad, you don't drive around in a car made in the country whose soldiers killed your best mate.
Oh yes, confront the past we are told, forgive, come to terms with it. Well, a better approach is to preserve one's ability to keep learning by not diverting our learning capability into learning how to be continually distressed by a past event. The brain is always learning, even if it is learning how not to learn- which is cognitive decay.
We are not here to be victimised by our memories. Choose the ones you want to preserve and shove the others in the box room and never go there. The belief that we cannot control our own thinking is one of the most pervasive myths of the present age. It has come about because 'control' is seen to be 'opposition'. Yet one can control thoughts as Buddhists have known for centuries by simply observing them and letting them pass. And when they have passed, not deliberately revisiting them.