As for me, I believe that if there's a God - and I am as neutral on the subject as is possible - then the most basic proof of His existence is black humor. What else explains it, that odd, reliable comfort that billows up at the worst moments, like a beautiful sunset woven out of the smoke over a bombed city.
Why do men delight in work? Fundamentally, I suppose, because there is a sense of relief and pleasure in getting something done - a kind of satisfaction not unlike that which a hen enjoys on laying an egg.