current algebras, broken symmetries, resonance phenomenology, particle supermultiplets, and Regge poles
Not that I know what most of those things are, but it took me right back: Regge poles! What ever became of Regge poles? Phys. Rev. was full of them in my day, but they haven't been in the news recently. Suddenly, a thought came into my head, fifty years after: They are poles in the scattering amplitude as a function of angular momentum continued into the complex plane. Wikipedia has an article on Regge theory, and damned if it isn't so! Physicists still learn about the subject, but it has become embedded in far vaster developments.
I was critical of both MSs, and in fact they never got published. However, after he became a professor, he did publish a book, about the campus politics of his university, and it caused some scandal. (I must look it up.) Then he had a heart attack on the tennis court & died. He is one of a number of people I wish I could donate my superfluous years to.
Many times a day I am reminded of things from a long time ago, as far back as childhood (70 years). But this one was exceptional in that it was not of something I was ashamed of.