How many times have you been asked that? How many times did you guess correctly? Once maybe... zero more likely, have you ever even responded? "Guess What" is the worst phrase/questions in the English language. It's a question designed to not be answered.
When you ask somebody "Guess What" you don't actually want somebody to guess, you just want to talk about something and think thats a friendly way to start the conversation. If you get asked "Guess What" you know you aren't actually supposed to guess... if anything your only response should just be "what?" YOU CAN'T RESPOND TO A QUESTION WITH HALF OF THE SAME QUESTION!!!!
But then there are those moments where that's not good enough... there are some mad anarchists out there who will actually make you guess. They ask "Guess What" you respond with "what?" as years of being part of civilized society has taught you to do and they respond with "guess" YOU CAN'T RESPOND WITH THE OTHER HALF OF THE QUESTION I JUST USED TO RESPOND TO YOUR ORIGINAL QUESTION!!! I don't have time for your mind games evil villain.
That's why I've taken to actually guessing when somebody asks me "Guess What," no matter what, using all possibilities in existence:
They've changed the name of North Dakota to Dakota #2? Porcupines no longer exist? People flying on airplanes are traveling through time fractionally faster than those of us on the ground? It's supposed to rain this weekend?
Now I'm more involved in the guessing than whatever your actual story is. Why do we all have to be the riddler when we have an interesting tidbit we would like to share? I'd like to hear what you have to say... Just don't ask me to guess what it is.