certainty vs daydream

certainty

noun
  • The state of being certain. 

  • A fact or truth unquestionably established. 

  • An instance of being certain. 

daydream

noun
  • A spontaneous series of thoughts while awake not connected to immediate reality. 

verb
  • To have such a series of thoughts; to woolgather. 

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