All hail Bill Watterson, Amole Gupte and Aamir Khan for understanding kids as they are.
The following are a few strips from Calvin and Hobbes that has been used rather directly in the movie. I wouldn’t say it is a blatant lift because am in love with that movie and am not going to say anything against it.
The below strip is a rather not so obvious inspiration. It is the shower fight scene that has been partially used in the movie; though the theological aspect in Calvin has not been brought forward in the movie. ‘The Universe has an attitude Mom!’; which 6 year old would actually say that? But well, Calvin’s been 6 for like ten years through the life of the comic strip; so he must have learnt a lot.