I didn't have any idea who Orson Welles was until I recognized him in school as the person that The Brain ('Pinky and the Brain' on Animaniacs) was a parody of.

To this day I've never seen Peter Lorre, but there was a quite distinctive caricature that repeatedly played on Looney Tunes, and it took half a day of Googling to figure out what that memory referred to.

There are lots of other reference jokes - repeated tropes, voices, facial poses, and musical themes assumed by these shorts that clearly carried some cultural meaning that we intuited by repetition, even if we never understood the source material. It's nice to have a "TVTropes For WB Cartoons" if only because we don't know the name of many of these things to be able to look them up.

Unfortunately the maintainer seems to be largely focused on the 1940's and early 1950's, with most of the references.