The case of the disappearing feet

Every morning Finn wakes up with big smiles. Often it's dark and he's bapping us in the face as he flails. Once he convinces us that we're awake and to stop pretending otherwise, he often gets sat up, at which point he starts trying to grab his feet (a favorite past time of his, especially lying on his back on the changing table) and seems to be a bit perplexed that they seem to have disappeared overnight (he sleeps in a sleep sack, which is like a sleeping bag with arms you button on), it doesn't bother him, he just is a little confused that he used to have feet, and he can feel feet, but he can't see them. Tonight he was singing, which was really just squeeking. I had both boy-o's today so Mama could go to the dentist. Finn thought it was funny when the stroller did big bumps.