The adult keeps advising the child about what he should do or should not do. But in the last two lines, the adult is expecting the child to make decisions for himself as if the adult has not been advising him about the dos and the don'ts. Yes the poet is suggesting that this is unreasonable because the child cannot decide what he should do or not when he is bound by instructions and prohibitions regarding each and every action he does. (The pronoun he has been used for the child in a general sense and does not depict the gender of the child.)
