W00:-
What a memory, and what a memorable man.
As with all good commanders, all you saw was the serene seemingly effortless scene on the surface. It came about only because of frenetic effort beneath. A friend of mine flew Sir Gus to inspect RAF Gibraltar (he was then the RAF Inspector General). Rather than relax in the sumptuous comfort of his VIP aircraft he studied the "rogues gallery" provided by his ADC for the entire trip. Everyone that Sir Gus had previously encountered and was now at RAF Gibraltar was the subject of avid revision, be they high or low. One such had been his driver in RAF Germany. Gus paused in his inspection of the Guard of Honour with a brief, "I hope your driving has markedly improved since I had a daily dice with death from it, Bloggs". Despite the teasing tone, Bloggs swelled with pride at being recognised, as did everyone else of course.
Your story likewise confirms that he had a memory that he could draw on in an instant. No doubt the result of constantly honing it so.
A great man and a great commander, but also a very human one. The guest of honour one night at RAFC Cranwell was a senior Luftwaffe General, who like Sir Gus had been a VSO in WW2. Gus ignored him all night. A very uncharacteristic slight from such a charming man, but then still waters run deep...