What most people secretly love about children is the child's innocent self-regard, what Freud calls the undiminished ego. People experience in children the memory of their own lost independence, selfhood, and pride
The exhortation to "be an adult," and "grow up" is nothing other than an arbitrary demand that you comply, conform, obey, submit to cruel and wanton authority, give up, surrender, abandon your hopes, your idealism, your essence, your soul, your life. That's what they mean