The song "Life Begins When You're In Love" by Billie Holiday is about the joy, happiness, and excitement that come with being in love. It celebrates the feeling of finding the one true love who makes the world a better place, and emphasizes how transformative love can be. The lyrics suggest that life truly begins when one is in love, as it brings a new outlook and perspective on life. The singer highlights the intensity and depth of love and the emotional rollercoaster that comes along with it - the sighs, longings, and cries. Cupid, the god of love, is mentioned as the one who brings two lovers together and sets their lives in motion. Overall, the song encapsulates the magic of falling in love and how it transforms the way one experiences life.