navel-gazing vs ruminating

navel-gazing

noun
  • Contemplation of one's navel as an aid to meditation. 

  • Excessive focus on oneself; self-indulgent introspection. 

  • (Disproportionate) concentration on a single issue. 

ruminating

noun
  • An act of pondering over, meditation, or reflection. 

How often have the words navel-gazing and ruminating occurred in a corpus of books? (source: Google Ngram Viewer )