Hear a song on the radio while driving down the road that just makes you smile?
For example every time I hear Boys of Summer by Don Henly I am instantly transported to a time many many years ago driving down the highway to get to an afternoon class as college. I can instantly feel the heat on my face and the wind whipping though my windows. It makes me smile and just feel all over good. Or here is one for the 80-90's You Spin Me Round by Dead or Alive. I am instantly out with my girlfriends a club. Dancing and having fun.