Joanne was much younger, and, altho they loved each other, both knew it was a "hopeless situation" because neither Joanne's family or Mike's family would accept the marriage, because Joanne was too young. And, Mike knew that Joanne loved "the man" (her father), and her father disapproved of him. Mike understood why, he probably has a daughter that HE loves, also. And, he also wants the best for her. Her father wanted Joanne to find a man more her age. It's a "Foster Harris 1 plus 1", where Joanne was forced to choose between 2 very good things: the love of her father, and the love for Michael. She chose her father, and Michael respected her for her choice, because "her father's hold on her was stronger than her love for him". Mike knew it was a hopeless situation, and, even tho they keep on loving each other, they both moved on, and forgave, so that love would bloom for others. Joanne's love for her father, above all else, made Michael love her even more. And, Mike's respect for Joanne even when she broke his heart, made Joanne love Michal more. Even tho this "love that can never be" wont be happening, its musical and spiritual beauty is here for the rest of us to behold.