I guess the main point that I would like to get across is that a lot of the "riddles" posted here are more like guessing games. No offense, MB^H^H Morgana Le Fey, but same goes for your in-game "riddle." A question is asked, and there could be many possible answers due to imprecise language. It all turns into Bilbo Baggins asking "What have I got in my pocket?"-- The guesser knows several things about the answer (ie, it's something that fits in a pocket, it isn't too heavy for a hobbit to carry it) but nothing in the question is precise enough to narrow the possibilities. This leaves the door wide open for me to tell a story about how
There's nothing in the riddle to rule this out, except that you've heard the only answer that you'll accept-- you know what you have in your pocket.
Again, I will agree that Trahern's answer is wittier, but there is nothing in the riddle that necessitates that his is the only possible answer.