Uncle Roy Giving Advice From the War Zone (WWII)

We were watching early episodes of Downton Abbey and I heard the sentence that was something like: In war you quickly learn what is important in life and what isn't. It reminded me of a card I once read from my uncle Roy from a WW II war zone in Europe to my mother. Apparently his sisters had another family family and all wrote him giving each side. Roy quickly wrote back and said he was seeing many deaths of friends every day and did not want to read about their petty bickering. Petty bickering! Petty? Get it?