absence of mind vs brain fart

absence of mind

noun
  • A state or the quality of being absent-minded (abstracted, preoccupied). 

brain fart

noun
  • An instance of absent-mindedness or forgetfulness. 

  • Something ill-considered and said or done impulsively. 

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