Signing time even when sleeping

You know that we're trying to get Ethan to learn Baby Signs. We have a couple of Baby Signing Time DVDs at home that Ethan watches a few times everyday. He's loving it and he's picked up a few signs.

A funny thing happened last midnight. Ethan woke up from his sleep and cried for milk, so I prepared a bottle for him and fed him while he went back to sleep. As he was half asleep, he raised his right arm up and started signing 'bird' (index finger touching the thumb forming a beak). I dismissed it as nothing.

Then after a few seconds, he raised his arm even higher and did an 'airplane' (thumb, index, and small finger extended, middle and pinky folded, like the Tina Paner 'I love you' sign). I said 'hmmmmm...'

Then suddenly, he started tapping his head. He's signing 'hat!' How cool is that? My baby is practicing his signs even when he's sleeping.

UPDATE: If you're curious about Baby Signing Time, here's a sample -


UPDATE AGAIN: As corrected by Lani, the 'I love you' sign is Sheryl Cruz', not Tina Paner's.