These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Hilarious in Hindsight: In a 1941 radio episode, Jack is bragging about a big party he's having and saying there will be a lot of big movie stars there. Mary asks him to name one- Jack refuses to answer. She badgers him to name one until he says, "All right- Rodney Dangerfield!" At the time it was just a funny name his writers made up, but now...
Memetic Mutation: "Yyyyyyyyyeeeeeeesssssss?" To the point that many people now have no idea where it came from, or maybe think The Simpsons invented it.
Tastes Like Diabetes: In an elaborate example of Jack's numerous Take Thats, after reading a radio critic's lament about how comedy of the day relied too heavily on insults, Jack invited said critic to his show (which was being broadcast from Palm Springs that day), and showed him just how awful comedy would be if there were no insults.
Done again in a Recycled Script television episode with the lamentation coming from the reverend Billy Graham.