Little things please little minds

Proverbial Meaning: Some people are too easily pleased by foolish pleasures. 

Literal Origins: The proverb pertains to children, who have undeveloped minds and like to play silly games that have little real meaning to an adult. 

Common Usage: This proverb is very well-known and often spoken, usually in a joke-like manner, to adults who appear to be deriving a lot of pleasure from a childish activity.