WE need School to be smart, if without school, no one would be able to become great people, look at the actors, famous people, where did they start off at??
Of course, school!!
another thing:
why does it last so long like 7 hours?
well, simple:
what would you do without school at home? i doubt you would be doing school work, or something related.
you'd watch TV, games, etc.
TO keep our minds concentrated on our life of educating, we keep working our brains out in school.
Hope this helped !=)