There were zero people in my office who knew what the Mikado was in the 1990s. Middle class, white, college educated, Great Plains folks.
But they mostly seemed to know nothing about Shakespeare except for a couple of speeches from Romeo & Juliet and Hamlet.
One of my coworkers referred to both as British Shit.
Looking at those co-workers pages on Facebook tells me they are in the same place culturally now and unfortunately so are their kids.
I am proud of the fact that I can provide a quote or a joke for EVERY possible situation using only the following three sources:
People who know me personally have told me, more than once, that they were surprised that I wasn’t an aficionado of midnight “Rocky Horror Picture Show” screenings back in the day. Oh, I knew about them; I just didn’t have any desire to go to them.
I have seen the movie, FWIW.
I thought EVERYONE knew Tom Lehrer.
(I was…mistaken. 
)
There are lots of movie theaters where it is now regularly played, as you can see in TRHPS Official Fan Site: Participation: Showtimes: Regular Showtimes .
A local theater screens it, with audience participation encouraged, every Halloween.
It just wouldn’t be the same at my age, although if someone invited me to join them, I probably would.
C’mon now - he’s 96. Granted he got sampled for a rap song about a decade ago, but realistically he hasn’t had much public exposure to wide audiences in quite awhile. I can’t imagine most people under at least 25 or 30 will know who he is. They were dragging him a little (or Mark Russell, or both) on The Simpsons for how dated he was back in 1991, when a substantial number of people might have still known who he was.
I’m surprised when I find someone who DOES know who Bazalgette was. He’s been mentioned on a lot of documentaries, but I guess I don’t know many documentary watchers in real life.
I’d never heard of him until about five years ago, when I was playing in a tabletop RPG set in late 19th century England. He was mentioned by the gamemaster, along with several others, as being among the engineering titans of that era, and we (the players, through our characters) interacted with him in the game.
Most of the reason his name sticks in my head is that it just sounds awesome: “BASIL-jet.”
I always thought that Isambard Kingdom Brunel sounded pretty awesome.
I’m 73. Tom Lehrer and Mort Sahl are the kinda folk whom I am familiar with their names, and know they were entertainers - mostly before I was old enough to consume their product. But not sure their performances themselves were relevant to later generations (as opposed to their stature as historical figures.)
I would’ve thought most people - at least theater/arts persons, would at least be familiar with G&S. Seems like almost every movie/TX show portraying a theater event chooses the Mikado. 
He makes a great cartoon character.
We are roughly the same age. In my youth I’d occasionally see Mort Sahl on the Merv Griffin Show, the one Merv did from the Little Theatre off Times Square in New York in the 1960s. So I was somewhat familiar with him. Tom Lehrer, on the other hand, I don’t ever remember seeing, other than seeing his LPs in the “Comedy” section of record stores. I actually didn’t hear anything of him unless that last couple of years, when I looked him up out of curiosity. His satiric songs are hilariously clever, and he was/is quite an interesting person beyond being an entertainer.
Typo? I thought you were 63.
Right you are. 63.
If you don’t know Tom Lehrer’s songs, a good place to start is a concert he did in Copenhagen on September 11, 1967 which you can find at https://www.youtube.com/watch?v=QHPmRJIoc2k .
I was at a weed dispensary and they had a strain for sale called Thelonious Funk.
“Heh,” I said, “Like the musician.”
Blank stares from the bud tender.
“Thelonious Monk?”
Nothin’.
That’s the kind of music they should have playing.
At my bro’s house we were talking about how their dog will steal food if you don’t watch him. I called him “a felonious punk”. My brother cracked up; his wife just stared, looking clueless.
There was a joke in a Terry Pratchett novel about something stolen by a felonious monk. I didn’t get it until my mother explained it to me.