von Neumann, Oppenheimer, Bohr, Einstein, Rutherford, Turing, Teller, Szilard, Wigner, Meitner... the list goes on... -- how did that time produce so many people of colossal intellect? War certainly can't be the primary factor, given that many of them were brilliant/productive even before WWI
https://en.wikipedia.org/wiki/Fasori_Gimn%C3%A1zium
Hungary had a great education system at the time.