...a life which is much, much more complicated after leaving school, serving in the military, having a career, starting a family, etc. If school has any value t

...a life which is much, much more complicated after leaving school, serving in the military, having a career, starting a family, etc. If school has any value to you at all, the utility of finishing school vs dropping out is higher earlier in life than later. Maybe for some people it makes sense to drop out (Bill Gates and Mark Zuckerberg being canonical examples). But for most people the decision isn't so clear-cut, and going back becomes tremendously more difficult as time goes by.