go for it vs undo

go for it

verb
  • To decide to do something; especially after a period of hesitation. 

  • To put maximum effort into achieving something. 

  • Used to grant permission for or to give endorsement of a suggestion or proposal. 

undo

verb
  • To unfasten. 

  • To reverse the effects of an action. 

  • To impoverish or ruin, as in reputation; to cause the downfall of. 

noun
  • An operation that reverses a previous action. 

How often have the words go for it and undo occurred in a corpus of books? (source: Google Ngram Viewer )