That definitely strikes a chord with me.  While I never found my high school or college math useful (except maybe to understand the ability to change 'reality' by how one actually set up a set of statistics;  and set theory did help a little when logical thinking was required) my grades at Duck U were much better than I had  in high school so I could be that 'late bloomer'.  Actually, four years in the Air Force after high school convinced me that there were things I didn't want to do and that college might open some different doors to things I would rather do.