Sleep Hammering

Last night my husband and I were cozily and soundly asleep in our soft, warm, comforting, womb-like bed when I was awakened by the sound of hammering outside. It must have been the city working on a water main or something. It was loud--and it sounded like a metal hammer striking an anvil over and over.
It was annoying, so I was trying to get comfortable so I could fall back asleep. I turned over, and to my amazement and utter surprise, my husband was lying on his back, and dutifully "hammering" the air in perfect time with the hammer noise from outside, using some kind of invisible hammer that was in his right hand.
I am not lying. I am not making this up. And I was not dreaming.
I laughed so hard, I almost peed the bed. And he just kept hammering on...