As someone who was one of the '1 in 30' ... that doesn't sound very frequent. For the ADD kid in the class, you are the class spazz. A walking joke. An easy target for both frustrated teachers and obnoxious kids.

And worse, because everybody suffers from inattentiveness at one point or another, people expect you to just 'Apply yourself, try harder.' 'Oh, I think I have ADD but do you know what I did? I stopped being lazy.'

This is not just a bored child. Just because something is a relatively common problem, doesn't make it not a problem. And if it is that common, then purhaps we need to reevaluate how to approach teaching so that it helps the whole class, rather than just the kids who are great at cramming and testing.

IMO, no one actually outgrows it. The adult ADD people I know have simple cobbled together clever coping mechanisms to keep up the pace with everyone else, and usually find someplace to work where they can apply their strongest assets, therefore struggling less.