We can glean glimpses of it in their writings, esp. in any current letters and oral histories. There's quite a chronicle of one of them, my dad's old friend, Floyd Coleman; a lot of experiences which I am sure shaped who he became. As of now, his latest goal is to be the oldest surviving WWII veteran. He's 94, rebuilds vintage autos and takes no medications...I think he'll make it! i love getting letters from him. Curmudgeonly, but still a gentleman.