People were so sharp in brain that once heard from the spiritual master, they will never forget. The brahmacari system made their brain so powerful that whatever they will hear from the spiritual master, they will keep in the brain and never forget. They will repeat verbatim. It is called retaining power. So God realization does not depend on material opulence.
Material opulence means to take birth in high family, janma.
Janma means high parentage. These four things are material opulences. Janma means birth, aisvarya means wealth, and sruta means education, and sri means beauty. So for God realization these things are not essential, but Krsna consciousness movement can utilize everything. So nothing is neglected.