i recently had surgery and was very limited in my activities for a few days before regaining some form of normalcy. My woo hoo, or contented sigh of relief, accompanied the departure of some of those limitations (to go further into detail might not be kosher). Woo hoo's, I think, often happen at the release of tension in one's life... just as in a significant amount of music, life can possibly be viewed of a series of rising tensions followed by release, sometimes better or more significant than other times. Even a surprise woo-hoo, like getting a raise, seeing a falling star, winning the lottery, a phone call from an old friend, will probably release some kind of tension that you didn't know was there...