I wonder if there are equivalent figures in other fields that we never hear about. Reminds me of László Rátz, who taught high school math to luminaries like von Neumann and Wigner (whose work forms the foundation of the math behind quantum mechanics, later worked on the Manhattan Project). Then again, Budapest at that time period produced a great many other world-class scientists and mathematicians (von Karman, of JPL and Karman line fame, Teller, from the Ulam-Teller nuclear bomb design, George Polya, Dennis Gabor), so maybe there are confounding factors there.