Nationalism is an infantile disease. It is the measles of mankind.
It is an infantile superstition of the human spirit that virginity would be thought a virtue and not the barrier that separates ignorance from knowledge.
Academics tend to have wonderfully infantile senses of humor.
I began my career with infantile dreams of becoming a composer.
We have domesticated God's transcendence. We often learn about God at about the same time as we are learning about Santa Claus but our ideas about Santa Claus change mature and become more nuanced whereas our ideas of God can remain at a rather infantile level.
Anyone can write a story based on the kind of horror where you see a guy in car and then there's the bad guy in the back seat. It's infantile to rely on that for telling a story. That's like going to bed and thinking there's a monster under your bed. It's silly.