You have a stack of books that you've accumulated over the years but from which you have never read a word. That stack might actually be taller at this point than the stack of books that you have read...
It seems a bit too overwhelming of a task to confront at the moment... you decide to do something less intensive first... maybe come back to it later... you're kinda tired and a bit hungry right now anyway.
Get something to eat
Take a nap