Proper dress, drill and deportment are the foundations of self-respect, and self-confidence, which breeds other - equally important - things in soldiers under stress in times of war... e.g.,
At Apeldoorn, Major Frank Lindley found himself in a room with about twenty other wounded Officer POWs. He says "We were all dirty and unshaven and in various stages of dress and undress. The door opened and in came RSM John Lord, also a POW. He was dressed in immaculate battledress, trousers creased, and he had an arm supported in a snow white sling. Without a word he turned his head slowly to look at each individual in turn and then said in his brisk voice "Gentlemen, I think you should all shave!" He then turned about, stamped his foot and marched out of the room. The effect was electric. The motley group of officers Infantry, Gunners, Engineers etc. stirred themselves and started to clean themselves up. It was an unforgettable experience". - quoted in To Revel in God's Sunshine; The story of the Army career of the late [Sandhurst] Academy Sergeant Major J.C. Lord, MVO, MBE, compiled by Richard Alford
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