Good behavior is rewarded, and bad behavior is punished

Dahl has a pretty clear message running throughout the book: if a character is nice, they will be rewarded, while those who are not nice are punished. The punishments usually stem directly from how the character behaves. If a character wants something too much, they subsequently receive much too much of it.

Charlie is a nice, friendly and brave kid. He is earning his place as owner of the chocolate factory. Charlie's Grandpa Joe is also congenial and always up for whatever was thrown at him. Nothing bad happens to these characters throughout the book.

Charlie's other grandparents, collectively known as the old ones, however, are mean, nasty, insulting people. They never want to get out of bed or try anything. Their answers to everything are negative. As a result, bad things happen to them throughout the novel...