"[Why] should one not speak like children?" - Nietzsche
I would say children are under less mind control than adults and certainly not as conventionalised meaning their sensibilities are generally closer to the truth than those of so-called grown ups.
German philosopher Karl Jaspers thought it a good idea in his Introduction to Philosophy, whose English title is Way to Wisdom, to write a collection of the ideas children express and examine them for their philosophical sophistication.
As far as I can make out, being an adult these days only really entails being legally allowed to watch pornographic material, smoke, drink alcohol, have sex, make money and bring forth more children.