gratification vs obstacle

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. 

obstacle

noun
  • Something that impedes, stands in the way of, or holds up progress, either physically or figuratively 

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