"If a man who cannot count finds a four-leaf clover, is he lucky? "

Stanislaw J. Lec

There are important questions that must be asked from time to time, such as, "If a tree falls in a forest and no one is around to hear it, does it make a sound?" Stanislaw J. Lec had another, "If a man who cannot count finds a four-leaf clover, is he lucky?”

Philosophical questions such as these make you wonder if the people who said them just had too much time on their hands. 

Another unanswerable quote is by C. S. Lewis, "Can a mortal ask questions which God finds unanswerable? Quite easily, I should think. All nonsense questions are unanswerable."

"If a book about failures doesn't sell is it a success?"

"What's another word for thesaurus?"

Here's one to go with our first one, "If a stealth bomber crashes in a forest is there a sound?"

"Do cemetery workers prefer the graveyard shift?"

OK, this could go on forever, so I'll close for tonight.