Right, you didn't know it was about fathers and sons because you probably didn't read the novel by Erich Segal - or, more specifically, the novelization that he wrote after the screenplay was accepted and undergoing the lengthy process of being developed into a major motion picture.
Basic story is this: Rich boy who resents his successful but elitist father falls in love with a poor girl whose relationship with her own father is warm, open, and nurturing. Misunderstandings ensue.
The problem with the WASP elitist father, Oliver Barrett III, is that he wants his son to be equally successful in all aspects of his life--sports, academics, love. (Success is, by man's definition, what happiness is.) Oliver IV is particularly resentful of his father's rejection of Jenny, who is not only poor, but also Catholic.
Though the audience is pretty certain of Ollie 4's love of Jenny, Mr. Barrett suspects that his son is merely rebelling against him by marrying this non-Abigail Adams ("or Wendy WASP").
Jenny tries unsuccessfully to help Ollies 3 and 4 better understand each other, and --- SPOILER ALERT ---
... she dies having failed in the attempt. Meanwhile, Jenny's dad bonds with Ollie 4 over Jenny's deathbed.
In truth, Mr. Barrett was quite charmed by the lovely Jenny and, if Ollie 4 hadn't been so antagonistic, might have put his prejudices aside eventually. When he learns Jenny is dying, he rushes to the hospital to be at her (and his son's) side.
"I'm sorry," says Mr. Barrett to Ollie 4.
"Love means never having to say you're sorry," Ollie 4 retorts.
Here's where the movie is different from the novelization. In the movie, actor Ryan O'Neal retains his frosty demeanor, stalking off to start his flashback about the girl who loved Mozart, Bach, and the Beatles. The "Love means never having to say you're sorry" lesson that he learned from his beautiful and brilliant wife turns into a rebuke to his father, a slap in the face.
Ollie 3 deserved better, and he got better in the novelization. Here:
MUCH better ending, in my opinion. Which is why it's one of my favorite Father's Day stories. If only Ryan O'Neal had let himself cry....
Update June 28: I see by my Yahoo News that Love Story stars Ali MacGraw and Ryan O'Neal have had another reunion. In this interview with Hollywood Reporter, Ali calls her famous line "a crock." Whatever, dude. (Didn't Candice Bergen say pretty much the same thing in the sequel, Oliver's Story? Maybe it was some other parody I'm thinking of.)
|Ali: "It's a crock." Ryan: "You'd better say you're sorry." Via The Hollywood Reporter.|
I've spent years (decades) trying to understand the line, but I think Segal's ending in the novelization illustrates it well: Love is compassion. Love is understanding. When it's mutual and complete, love encompasses an unspoken forgiveness that doesn't require or demand a statement of contrition.