commonplace vs unforgettable

commonplace

noun
  • A platitude or cliché. 

  • A commonplace book. 

  • Something that is ordinary; something commonly done or occurring. 

  • A memorandum; something to be frequently consulted or referred to. 

verb
  • To make a commonplace book. 

  • To enter in a commonplace book, or to reduce to general heads. 

adj
  • Ordinary; not having any remarkable characteristics. 

unforgettable

adj
  • Very difficult or impossible to forget. 

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