Oh, say can you sing?

I've enjoyed the Olympics immensely. Our American athletes have not disappointed--too many remarkable performances to name here, but it's been an extraordinary showing. But what's up with our athletes not singing (or mouthing) our national anthem on the medal stand?

I can't even imagine what goes through the mind of someone who's trained tirelessly for years to arrive at the pinnacle of an athletic career. It must be heady, emotional, joyful, surreal, ______. But are they so overcome with emotion that they can't sing our country's patriotic hymn? Or do they not know the words? Either way, it irks me, particularly when athletes from other nations are seemingly much more inclined to proudly sing their anthems.