whys and wherefores ofthe whys and wherefores (of something)
the reasons for something.
The movie doesn't spend much time worrying about the whys and wherefores of its stars' behavior.
whys and wherefores of something
the reasons or causes relating to something. I refuse to discuss the whys and wherefores of my decision. It's final. Bob doesn't know the whys and wherefores of his contract. He just knows that it means he will get a lot of money when he finishes the work.