Your sudden idea was that the answer to the riddle was a human being.
That couldn't be right, could it? you think. You spend the rest of the two minutes trying to think of another answer. Finally, you hear the loud voice of the Sphinx; "Time's up!" Then she exclaims, "Why, I thought you would be smart and wise. But I was wrong. You are not worthy to be here. Now you shall pay the price for trespassing on my forest."