You know, I've been thinking that what I have *not* seen (or at least don't remember seeing) is a study/discussion in which actual gifted (and hopefully successful) adults say what was best and worst about their K-12 education. This might end up being just a collection of anecdotes, and since the educational system has changed a lot over the past few decades it might not be entirely applicable to the current systems, but I think it would be interesting at least. I've heard stories, but usually just about one person at a time.
