recollection vs thoughts of the past

recollection

noun
  • The act or practice of collecting or concentrating the mind; concentration; self-control. 

  • The act of recollecting, or recalling to the memory; the act of recalling to memory. 

  • That which is recollected; something called to mind; a reminiscence. 

  • A spiritual retreat, especially one that is short. 

  • Process of collecting again. 

  • The power of recalling ideas to the mind, or the period within which things can be recollected; remembrance. 

thoughts of the past

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