Ego is forgottten innocence is more in children, equality is realised. Helping nature is developed team spirit is high while participating in sports events. Feeling of oneness and belonging is established. Their uniform speaks about them. They learn a lpt from their seniors and teachers. Many schools which promote NCC Scouts and Guides prepare children to face the challanges of the outside world. Discipline is the topmost priority of school life. All these are foundation steps for a healthy disciplined life of an individual.
Yes, school is a formative period in one's life, because a person's basic personality is more or less set by the time they are an adult. A person changes so much based on their experience in school. It usually determines his or her entire career. School is a critical period in any young person's life.
Many young adults find college and higher education as a place to learn more about themselves. This is a time away from parents and other authority figures that may hinder people from expanding their lives. Many friendships and life long contacts will be made during this crazy but life altering time.