He was asked by the interviewer how someone like himself, a Westerner, had learned the arts.
He explained that one day a man wearing face paint and tribal dress appeared out of thin air in his living room and said to him, "Come see me," then vanished.
The American was living a completely ordinary life and had no knowledge of native cultures, but when something like that happens to you, believe you me you get yourself to libraries and bookstores -- or today there would be a lot of research online.
Finally he determined that the mystery man was likely an Australian aborgine. So he went to Australia, sought out aborigines, and described for them the man who'd appeared in his living room.
Someone said oh yes, you're looking for so and so; he's a healer. He named the man and gave the American directions for where to find him.
When he arrived there was the man who'd appeared to him. Without any greeting the healer told him that now it was time to continue his studies. That was that.
As to how many 'lifetimes' he'd been a student -- many enough that the teacher didn't waste money on a postcard to tell him vacation time was over.