heed vs thoughtlessness

heed

verb
  • To mind; to regard with care; to take notice of; to attend to; to observe. 

noun
  • Careful attention. 

thoughtlessness

noun
  • heedless disregard for the consequences of one's actions 

  • disregard for other's feelings 

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