My girls always got very "active" if there were singing and dancing and tons of stimulation, but I have always been shocked that my DD5 sat quietly, almost motionless, listening to stories starting at about 3. It is so unlike her. In general she is overly excitable, talkative, and active, yet storytime hypnotizes her so if I needed a break, we'd go so she could zone out on the stories and pictures. Things may change for you, but if they don't, no big deal. There will be other activities that suit him better.
My Dd went to preschool and it might have been that experience that helped her learn to contain during circle time (not sure if you think that is all good). Yet, she still can get over excited, loud, talkative, and busy in many settings, including group settings. The only time she really gets quiet is if they are reading a story or doing a puppet show.
