...but it's because I've been far too busy lying perfectly still, and allowing myself to be repeatedly kicked. Pretty masochistic, I know. I presume that after the birth, I will no longer find it a good thing to be kicked. Until then, I plan to enjoy it as much as possible.
Drawing from http://en.wikipedia.org/wiki/Proportional_reasoning, and accompanied by a simple math problem. It came up first on a Google image search for the word 'short'.