I was dunked at 12 or 13. The summer between 6th and 7th grade. The dubs in our area looked down on other children past the age of 15 who hadn't been to the pool. They even when so far as to critisize their parents, behind their backs. The feeling was that they had to get their children locked in before they got old enough to be "influenced by the world". Funny part is that it has backfired. Out of all the young people I grew up with, very few are still in. I would say 10-15%. I have 2 sisters and 1 brother. NONE of us are still in. ALL my siblings are DFed, except for me.
Around me, I'm seeing an exodus of young ones from the Matrix. Especially if they can get to college. Very few go to college and remain DUBS. Maybe that's why the GB has had to snap them back from the 4 year degree path.