“. . .he had little in common with Lot’s other son’s.  Nor did he have Gareth’s
passion for arms and knightly things, nor so far as she could tell, Morgaine’s gift for music, though his voice was clear, and sometimes he would bring out a little set of pipes like those the shepard lads played . . .”
 “. . .Still, he had a quick and retentive mind. for three years, Lot had send for a
learned priest from Lona to dwell in their house and teach the boy to read . . .”
 “. . .Gwydion soaked up every bit of learning, it seemed, as quickly as it was put before him.  Within a year he could read as well as the priest and speak in Latin as if he were one of those old Ceasars reborn, so that for the first time Morgause wondered might there not be something, after all, in what the Druids said--that we were reborn again and again, learning more and more in each life.” (459)

 Gwydion is something of a child prodigy, impressing all that see him with his
intellect and ability to make crafty counsel.  He also is strongly gifted with the sight, like his mother.
 
 Bradley, Marion Zimmer. The Mists of Avalon.  Alfred A. Knopf, 1982.