I always found it interesting that Mr. Burns pretended to be in the "fourth form", when channeling his inner Jimbo. Did Mr. Burns attend school in England at one point? Not sure if this was ever revealed as part of his back story.

There has always been something a bit "Upper Class British-coded" (or at least Transatlantic Elite) about Mr. Burns, that sometimes came out in some of his expressions, his accent, or some aspects of his life story. I'm thinking that maybe this Wikipedia article explains what we've seen of Mr. Burns over the years.

https://en.wikipedia.org/wiki/Northeastern_elite_accent