> One can drop out of highschool, then years later, take the necessary tests, then go to college.

You have conveniently glossed over events in those missing years. Did they get proper stable environment to live in, did they get enough food to eat, did they have somebody encouraging them to go to college etc. Events in those intervening years are what breaks you down or builds you up enabling you to go to college or not. In a sequence of events you cannot omit some and highlight some according to your disposition. That is called "false advertisement".