TKG:What we know of Srila Prabhupada, we know from after he came to America; we don’t know everything that happened before that, and we certainly don’t know how Krishna and he are related. Prabhupada was able to hear from Krishna everything he needed to know. Prabhupada’s learning is a combination of both his studying and also Krishna’s revelation to him.
Source: Remembrances by Sidhanta Das – Folio Vedabase