mistake vs notion

mistake

noun
  • An error; a blunder. 

  • A pitch which was intended to be pitched in a hard-to-hit location, but instead ends up in an easy-to-hit place. 

verb
  • To understand wrongly, taking one thing or person for another. 

notion

noun
  • An invention; an ingenious device; a knickknack. 

  • Mental apprehension of whatever may be known, thought, or imagined; idea, concept. 

  • A sentiment; an opinion. 

  • Any small article used in sewing and haberdashery, either for attachment to garments or as a tool, such as a button, zipper, or thimble. 

  • Inclination; intention; disposition. 

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