Puerility
Part of speech: noun
Definition: The state, quality, or condition of being childish or puerile.
Childhood
Part of speech: noun
Definition: The state of being a child.The time during which one is a child, from between infancy and puberty.The early stages of development of something.
Example sentence: I spent my whole childhood wishing I were older and now I'm spending my adulthood wishing I were younger.