Our own little dawn chorus

The little man has always been a good sleeper. From six weeks old he had worked out that when it gets dark, the best place to be is in bed and often wouldn't stir before 8 the next morning (I can hear all you sleep-deprived parents grinding your teeth as I write this and I don't blame you - going without sleep is afterall a known form of torture in some countries).
So when he does wake up in the night, it is always a bit of a shock. It happened recently when our friends, who are trying to decide if they are ready to become parents, were visiting. They came down for breakfast the next day bleary-eyed and concluding they might delay any baby plans for a few more months at least.
And it happened again just last week. The first thing I noticed was a little voice in my dream saying "mummy, mummy" and gradually these croaky words began pulling me out of a blissful slumber and into the grim reality of a 3 o'clock wake-up call.
I stumbled into his room where, bright-eyed, my son stood singing to me. He was worryingly lively for such an early hour and no amount of warm milk and story-telling would persuade him to be otherwise. In the end I  broke all the rules and brought him into our bed.
While his daddy and I lay there, eyes closed and trying to sleep, he bounced about in between us having a wail of a time. We tried to ignore him, hoping sleep would eventually come, then clearly and with all the actions, he unleashed a perfect rendition of Wind The Bobbin Up all the way through. I have sung this to him pretty much from birth and he has never shown any signs of knowing the words let alone the accompanying moves. It was truly beautiful.
We might have suffered for it the next day but there wasn't anywhere else I would rather have been than lying awake at four in the morning listening to our clever little songbird. I just wonder what else he has been up to when we have been fast asleep next door.