There's a British panel show I'm addicted to (QI), and one of the frequent guests in its earlier seasons was American comedian Rich Hall. I always thought that he looked strikingly similar to Moe Szyslak but just chalked it up to coincidence.
After years of wondering, I finally bothered to look up who Moe was actually based on. Lo and behold, it's Rich Hall.
So, I guess it's less "today I learned" and more "today I confirmed my random theory".
Interesting, he doesn't look anything like Moe here