When my sons were about 6 and 7 or so, we were sitting at the dinner table and the older one said, "Mom, when's your birthday?" The younger one immediately piped in with, "Duh, it's the day she was born!" Kids are so funny - without even knowing it! He couldn't figure out why his answer cracked us up!! Another time, about the same ages, the younger one was mad at his brother who had locked him out of his room and was ignoring him. He slipped a very miss-spelled note under the door that said, "big whoppy do to you!"