Puer aeternus

Puer aeternus is Latin for eternal boy, used in mythology to designate a child-god who is forever young; psychologically, it is an older man whose emotional life has remained at an adolescent level. The puer typically leads a provisional life, due to the fear of being caught in a situation from which it might not be possible to escape. He covets independence and freedom, chafes at boundaries and limits, and tends to find any restriction intolerable.