why did my super clingy puppy suddenly go cold?

My puppy used to be all over me 24/7—zoomies, cuddles, dramatic welcomes at the door. But since yesterday? Nada. He’s just been lying around the house like a fluffy little statue. Doesn’t really follow me, doesn’t paw at me for attention like usual. Food and bathroom habits are totally normal. No limping, no signs of illness. Just a sudden switch in attitude and energy. Anyone else's pup ever do this? Do they just wake up one day and decide to be mysterious or should I be worried? #puppylife #moodshift #dogowners