"The popular view that a child forgets easily is not an accurate one. Many people go right through life in the grip of an idea which has been impressed on them in very tender years."
("Murder in Mesopotamia", Agatha Christie)
It is true that in the early stages of childhood, a human mind is especially vulnerable to both positive and negative influences.
Beliefs, perceptions and values ingrained at a young age can define an entire life of a person.
Sometimes, our childhood observations and experiences can lead to a notion, good or bad, getting firmly fixed in our mind, and that becomes a dominant aspect of our personality, and can even translate into an inspiration or an obsession, that greatly impact our actions, for the rest of our lives.