I've been trying to figure out what it is I feel when I'm in our Airstream. We just moved in last week to start our full-timing travels, and each day that goes by I am more in love with living in it. It not only is our home, it feels like home.
Someone else mentioned a cocooning effect and maybe that's it, feeling wrapped up and safe in our Airstream cocoon. Or I've been thinking how when I was a kid I wanted my own little (tiny) house or fort all my own, and that perhaps those childhood feelings are evoked from being in the Airstream.