That doesn't account for all of the difference. I went to public HS in rural Sacramento county, while some friends of mine went to the public schools in nearby

That doesn't account for all of the difference. I went to public HS in rural Sacramento county, while some friends of mine went to the public schools in nearby Folsom -- a very wealthy suburb. These were public, like I said, so they don't have that selectivity you mentioned: if you live in their district, you go there. "Just" the facts of very interested parents, investment from nearby Intel and HP, and massive spending on technology programs were enough to set this school apart. Sometimes the simple answer is the right one.