I have a 5 yo and 15 yo- both boys- and the younger one fell in love with the Walter books. I even asked the 15 yo to read to him in the car and he grudgingly took the book, without even reading the title and by the 3rd page- even he couldn't help himself! Walter books are amusing, but they also teach a valuable lesson about unconditional love and accepting others even- even if they have "flatulance issues"!