There was the Nazi regime," Benedict said. "We were told very loudly that in the new Germany 'there will not be anymore priests, there will be no more consecrated life, we don't need this anymore, find another profession.'" "But actually hearing these loud voices, I understood that in confronting the brutality of this system, this inhuman face, that there is a need for priests, precisely as a contrast to this anti- human culture," he said.
Not that it was a simple decision.
I asked myself if I really had the capacity to live an entirely celibate life," he said. "Being a theoretical and not practical man, I also knew it wasn't enough to love theology to be a good priest, but I also needed to be available to young people, old, sick and poor people." He said that in the end, God as well as friends and other priests helped him to decide.
This in response to questions from young people. I'll try to find the transcript of the whole meeting. Curtsy to the Anchoress.