"That varies from world to world. In most of my sets of memories, I was born with the potential and my teacher took me in. In one set however... only some people could, and who they were was an unknown until their teens generally. There were some who considered us less than human, some who considered us more. Some who just saw us as other. Our very existence in that world was a point of conflict."

Thankfully she was mature enough not to feel stung by the emphasis on human. Sh had a feeling it would have upset a number of her students.