I emerged from secondary school in 1967, aged 18:
immature, inexperienced, indoctrinated, ignorant, repressed, uninformed, misinformed, misled yet opinionated but otherwise discouraged and demoralized;
unprepared for higher education, work, life or personal relationships;
unable to speak any foreign language although I had supposedly been taught one for the previous six years (however, "French" was a subject to be passed, not a language to be spoken).
Did I get anything from school apart from University entrance exam passes? An introduction, but only an introduction, to study, spirituality and sport. I did not want the sport. I had to develop personal study skills at University several years later. I have changed my spiritual practice twice since birth:
our starting point is determined by parents or society;
we might experiment with an alternative early in life;
we then find which path is most beneficial for us.
So two changes is far from excessive.
What was wrong with that school education? I soon came to disagree with schools that are fee-paying, boarding, single sex or denominational. So the answer is everything.
10/7/13: Any education is an interaction between the institution and each individual. I started out with very definite personal failings and limitations which were exacerbated by the education.