Education systems across America are very different. Poor (including rural) districts have a very hard time getting decent funding and, therefore, good teachers.
I was fortunate to have a decent public education and parents who trusted the teachers. This is not the case across the board.
Age of credit is a factor that goes into calculating scores, and so are number of open accounts. Changes to both of these could be detrimental, but it really depends on what the rest of your credit looks like.