brain fart vs folly

brain fart

noun
  • An instance of absent-mindedness or forgetfulness. 

  • Something ill-considered and said or done impulsively. 

folly

noun
  • Foolishness that results from a lack of foresight or lack of practicality. 

  • a pinkish-red color 

  • A fanciful building built for purely ornamental reasons. 

  • Thoughtless action resulting in tragic consequence. 

How often have the words brain fart and folly occurred in a corpus of books? (source: Google Ngram Viewer )