This is one of my favorite topics to discuss.
A very, very essential book to read on this topic is John Taylor Gatto's
Underground History of American Education which is available free to read online at:
Table of Contents - John Taylor Gatto
It covers how school affects people psychologically. Namely, that the school structure itself promotes certain tendencies. It promotes people to be externally motivated both with regards to an authority figure and to become more like their peers (aka sheep). It stifles individual creativity and the fulfillment of personal goals.
To understand why school doesn't cover things which would so obviously only benefit people is to understand the purpose of public institutionalized compulsory schooling. You have to imagine yourself as the ruler of a country, as a king, dictator, or in capitalism as the titan's of business. You have certain goals. You want a stable working system with yourself at the top. You create two sorts of school systems, one for the class of people that make the decisions and one for the class of people that follow decisions. The first one creates people that are much better at following their own internal motivations and to accomplish their goals. These people are better suited for making decisions that shape a nation. Unfortunately, you can't have everybody trying to make decisions at the same time. If everybody had an influence, then the system would be too unpredictable. It would control itself and you most likely wouldn't stay on top. So you create a school for the common people which is designed to keep them on the bottom.
As a capitalist, you want people working for you, not as entrepeneurs. You want people that follow directions well and don't rock the boat. Public school is designed to shape children into those people. In America it was shaped by Rockefeller and Carnegie in the early 20th century and was based on the prussian school system.
It would be against the school systems interests/base goals to teach children personal development or entrepeneurship. It's really, really sad. When I look out at the population, I see so much pain that is caused directly from people not knowing or understanding their true selves. How many people are working in jobs that don't personally fulfill them? How many midlife crises are their when people snap out of autopilot mode and say to themselves, "holy Sh!t, what have I been doing with my life?" How many drugs are taken, suicides done, eating disorders started, etc just because people can't cope with trying to fit themselves against an external model? Those are the symptoms of the separation of the true self and false self aka the ego which society (helped along greatly by school) shapes for them.
School should be designed to promote each individuals uniqueness. To teach them to fulfill their life missions. It shouldn't be used to force them to fulfill someone else's plan for them.