Talk:Amon/@comment-3478959-20120605224555

There are only two known applications of energybending: The ability to transfer knowledge, as shown by the lion turtle when he granted Aang the knowledge of energybending,[1] and the ability to remove another person's bending, as shown when Aang removed Fire Lord Ozai’s firebending.[4]

This is an excerpt from the energybending article, take note of the passing knowledge part. Maybe Aang passed the knowledge to Amon when Amon wasn't behind the mask.