What is it about sleeping kids?

Kent has been getting into trouble lately. Yesterday he dumped out 2 water bottles  on the carpet in my room and then proceeded to smash the water bottles. Then later he climbed onto the table and jumped off onto the beanbag. He had a sippy cup in his mouth. Well when he jumped onto the beanbag he bounced off backwards, hitting his head on the ground and making water go everywhere. Then later again, he was supposed to be washing his hands but instead he was making a huge water mess all over the bathroom. Then another time he got into the closet where we keep our camping stuff and got out a bunch of stuff and made a big mess. And between all of this he is getting into the fridge and the pantry because I think he's growing because he is always and forever telling me, "I'm huuungwy!" I took all three kids to the store yesterday by my self and let me tell you, I couldn't get out of there fast enough because of this little one trying to "help" and put random things into the cart. But then just about them time I feel like I want to cream him, he runs up and gives me a huge hug and says "I wub you mom!!" Or he looks at Elijah and says, "I wub your baby mom!" Or "I wub his nose" (or other various body parts). He is about as busy as can be, but also as sweet as can be. He loves his brother and sister, and rough housing with dad or reading books with mom.  Also about the time I want to cream him (which often coinsides with nap time frequently) I catch a glimpse of him like this: 

How can you be mad at a sweet face like that? What is it about sleeping kids that just melts your heart? It makes you realize that all the cleaning up water messes and craziness is all worth it. My kids are worth it. Worth feeling tired, worth having a messy house, worth all of the time spent on them. They are totally worth it. I have the best job ever!