can't wait vs look ahead to

can't wait

verb
  • To eagerly anticipate; to find it hard to wait for a forthcoming pleasurable event. 

  • To need to be attended to right away. 

look ahead to

verb
  • To plan for the future; to look forward to something; to be excited for something happening in the future. 

How often have the words can't wait and look ahead to occurred in a corpus of books? (source: Google Ngram Viewer )