When you hear the word "Why?," you know you've got one of the biggest unanswerables on your hands, such as "Why are we born?" or "Why do we die?" and "Who do we spend so much of the intervening time receiving junk mail?"
Or this one:
"Will you go to bed with me?"
There's only ever been one good answer to the question "Why?" and perhaps we should have that in the alphabet as well. There's room for it. "Why?" doesn't have to be the last word, it isn't event the last letter. How would it be if the alphabet ended, "V W X Why? Z," but "V W X Why not?"
Don't ask stupid questions.
Douglas Adams: The Salmon of Doubt