Many of Calvin's struggles are metaphors of Bill Watterson who believed that most of us get old without growing up, and that inside every adult(sometimes not very far inside)
is a Bratty kid who wants everything his own way.
We never do anything fun," for example,
might translate to something far less Bratty, like,"I would really like to go to the movies,
even though no one else in the family likes it as much as I do, can I have a say this time?"?