Acharya Prashant explains that the human brain is a product of evolution and serves as the seat of intelligence. He notes that the brain is not fully ripe until the age of ten to fourteen, making it necessary for children to depend on external information and guidance from parents. This dependency is described as a natural state of ego due to being small and helpless. However, he emphasizes that once an individual reaches maturity, it becomes an obligation to act through one's own intelligence rather than remaining dependent on external rules like a child.