'Coatl
Teotzlcoatl
A shaman is born with a gift and depending on the culture it is either encouraged or squashed but the gift is born in not learned. The gift can be honed by learning but cannot be created no matter how long you study. It is like becoming Buddha, unless one is born Buddha one can only become buddah-like.
Umm... have you ever read anything about Buddhism? Your totally wrong. The Buddha himself says that every being has a "Buddha-nature"? Where the hell did you get that? Tell me what a Bodhisattva is?
I also believe that while a shaman may be born with certain gifts, many shamans are trained and learn to become shamans.