Probably true but I also posted above that it could also have been a matter of him about to be drafted so he joined the Merchant Marine. And soon after shipping out the War ended so he returned to his beloved long afternoon naps.
I had an Uncle that could go like your Uncle Marty. Then one day he had a stroke and lost his ability to articulate. Very frustrating for him. It was hard to communicate simple things in his life, let alone the complexities of jocularity. My greatest joy with him was getting a laugh or chuckle out of him the last 4 or so years of his life. Here’s to all the Uncle Martys out there, long may they reel them off.