difficulty vs gratification

difficulty

noun
  • The state of being difficult, or hard to do. 

  • Physical danger from the environment, especially with risk of drowning 

  • An obstacle that hinders achievement of a goal. 

  • An objection. 

  • An awkward situation or quarrel. 

  • That which cannot be easily understood or believed. 

gratification

noun
  • The act of gratifying or pleasing, either the mind, or the appetite or taste. 

  • A gratuity; a reward. 

  • A feeling of pleasure; satisfaction. 

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