Childlike wonder and delight in the universe vs. jaded adults
Children have a natural curiosity for the world around them as we are shown through the repetition of the interrogative wh-words of the speaker who is assumed to be a child in this poem. Adults conversely have been around long enough and are no longer curious about the makeup of the world. Their focus has shifted from curiosity to that of survival. Represented by the speaker's father, adults are of the mind that answers to triviality are inconsequential. The father adopts a devil may care attitude towards the questions of his son and this subsequently leads the child to wonder why "Dad won't tell me, if he knows?"