Conformity is a narrowing of the mental scope. It's an understanding that the world is the way it is. That there is a goal of life, and that goal is to find one's place within this set world. This worldview isn't innate. It's learned, perpetuated. By parents. By teachers. By friends.
Although the connotation is often negative, the world needs conformists, and in much more abundance than nonconformists. They both serve a vital role in the academic and artistic advancement of humanity. Survival, and flourishment, rely on a certain balance of both worldviews in the population.
"What do you want to be when you grow up?", an all too common question asked of children. Merely by asking this question, one is teaching the essence of conformity: the world is set, and you must find your place within it. One's answer to this question might evolve, but it's by reflecting on the question itself that conformity is being learned (a nonconformist would answer "an artist", or "I want to be me", both a healthy dismissal of the question). This question also instills another key tenet of modern conformity: you are what you do for money. The question isn't "what do want to do for work", it's "what do you want to be". The language chosen is a reflection of the poser of the question's worldview, hence the perpetuation. There's also the expectation that there will be a singular answer to the question: "a doctor", "a lawyer", "an engineer", an enforcement of specialization. Once a determination is made on which of these preordained paths will be followed, emulation of those who chose that path before ensues: what to study, where to live, how to dress, what company to keep. The narrowing, the calcification of habits, of beliefs, of life path, has begun.