lose the thread vs ramble

lose the thread

verb
  • To get distracted and lose track of something (one's train of thought, a conversation). 

ramble

verb
  • To talk or write incessantly, unclearly, or incoherently, with many digressions. 

  • To lead the life of a vagabond or itinerant; to move about with no fixed place of address. 

  • To follow a winding path or course. 

  • To move about aimlessly, or on a winding course 

  • To walk for pleasure; to amble or saunter. 

noun
  • A leisurely stroll; a recreational walk in the countryside. 

  • A bed of shale over the seam of coal. 

  • A section of woodland suitable for leisurely walking. 

  • A rambling; an instance of someone talking at length without direction. 

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