Adoption
http://www.stevegrande.com/adoption/

... adoptees recognize Peter Pan as a brother. They, too, become lost children when they separate as babies from their natural families and disappeared into a place very much like never-never land. Like Peter, they are fantasy people. Denied the right to see their real birth certificates and the names of those who brought them into the world, they can't be sure they even had a real birth day. They can never grow up because they are always referred to as an "adopted child." [From Journey of the Adopted Self, A Quest for Wholeness by Betty Jean Lifton.]