...is that they live completely in the moment.
If you allow yourself to join them there, you will inevitably find yourself in a peaceful, happy place.
What brings this to mind? I'm sitting beside the office desk, with my feet propped up on it while DH does some e-mail chores. Little Candy has deserted her siblings in favor of playing on my lap, using my legs as a bridge to the desk. She is completely involved in her play, chasing one thing, then another that distracts her. DH can't continue the e-mail. It's too much fun to watch her play.
BTW, that's Chip on the left. He reached his goal weight of 2 lbs on Thursday. Candy is on the right. She is up to 20 oz. today. I suppose some would think her homely, but I think she is just the cutest thing, shadowing me wherever I go. She and Chip are best buddies.