Do I have drool coming out of my mouth yet?

Tonight before his bath I asked my oldest what he was thinking about, I thought he looked like someone deep in thought, his response?

"Is there drool coming out of my mouth and down my chin yet?  Because I don't feel anything, not sad, not happy, not mad, just nothing."

I wasn't sure how to respond to that so I just said, "Do you usually have drool coming out your mouth and down your chin?" He just laughed and said that he was happy....