The traits the word 'childish' addresses are seen so often in adults that we should abolish this age-discriminatory word when it comes to criticizing behavior associated with irresponsibility and irrational thinking.
If I had been helping the Almighty when he created man, I would have had him begin at the other end, and start human beings with old age. How much better to start old and have all the bitterness and blindness of age in the beginning!
We [women] have borne and bred and washed and taught, perhaps to the age of six or seven years, the one thousand six hundred and twenty-three million human beings who are, according to statistics, at present in existence, and that ... takes time.