forget vs look back

forget

verb
  • To cease remembering. 

  • To lose remembrance of. 

  • To unintentionally not do, neglect. 

  • To unintentionally leave something behind. 

  • Euphemism for fuck, screw (a mild oath). 

look back

verb
  • To reconsider or regret. 

  • To think of (past events) in retrospect. 

  • Used other than figuratively or idiomatically: see look, back. 

How often have the words forget and look back occurred in a corpus of books? (source: Google Ngram Viewer )