I just finished reading this biography of the physicist Enrico Fermi, "The Pope of Physics" and while he was obviously very talented from a young age, there were a lot of points in his career from Italy to the United States where luck played a critical role. He was lucky that he was taken under the wing of a senior academic early on, well before he became famous or did any really significant work. That figure ensured that he and several other young physicists got academic appointments (when others tried equally hard to block those appointments, and put their favored proteges in those slots). He was also lucky that he was able to escape fascist Italy with his Jewish wife, and emigrate to the United States.

However, it also kind of backs up the thesis here, as Fermi apparently worked very hard to lose his Italian accent once in America, as a means of more effectively communicating with the locals. He then became the leader of the Chicago reactor project, then an all-around consultant for the Los Alamos Manhattan Project.