brain fart vs preoccupation

brain fart

noun
  • An instance of absent-mindedness or forgetfulness. 

  • Something ill-considered and said or done impulsively. 

preoccupation

noun
  • The state of being preoccupied or an idea that preoccupies the mind; enthrallment. 

  • The act of occupying something before someone else. 

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