No matter how much fun you have somewhere else, returning home is a comfort. Sleeping in one's own bed, having access to all one's own stuff...the human nest we create is usually soothing to ourselves.
Here's a pic, or two, of my boys:
It doesn't have anything to do with vacation. I just can't look at them without realizing that they already possess the I'm-too-cool-for-my-own-good attitude that will only grow larger as they edge towards pre-teen status in the next couple of years.