Dance

as though no one is watching you,

Love

as though you have never been hurt before,

Sing

as though no one can hear you,

Live

as though heaven is on earth.

attributed to Souza (not John Philip, though)

http://www.flickr.com/photos/ethekwinigirl/949778374/

I’ve also seen this nearly-identical variation attributed to Mark Twain:

“Dance like no one is watching. Sing like no one is listening. Love like you’ve never been hurt and live like it’s heaven on Earth.”

No matter who said it, even just doing two of these is transformative. (and fun!)