The people who receive the most approval in life are the ones who care the least about it--so technically, if you want the approval of others, you need to stop caring about it.
That was what, ultimately, war did to you. It was not the physical dangers--the mines at sea, the bombs from the air, the crisp ping of a rifle bullet as you drove over a desert track. No, it was the spiritual danger of learning how much easier life was if you ceased to think.