written by Don Raye and Gene DePaul. 1941 MCA Music Publishing ASCAP. You don't know what love is. Until you've learned the meaning of the Blues. Until you've loved a love you had to lose. You don't know what love is. You don't know how lips hurt. Until you've kissed and had to pay the cost. Until you've flipped your heart and you have lost. You don't know what love is.