This story ends with this poetic line: "Love is never having to say you're sorry." That's very dubious advice, but it is also a powerful metaphor for love's true purpose—to forgive. The movie is artistically similar to the contemporary song, "What Sarah Said," by Death Cab for Cutie which states, "Love is watching someone die." That is absolutely the case in this story, because Oliver starts the movie hoping love with give him something, but love was not about gain.
The moral of the film might be love, but the purpose of the plot seems to be to take the audience's understanding of love and to warp and twist it the way life so often does, until love isn't about feelings or fulfillment. Oliver has to mature to the point where he sees love as something that not only doesn't fix his personal problems but transcends those issues completely. This is especially evident in the ending.
When he makes peace with his father, that is proof that his love for Jenny transformed his ability to understand relationship. Instead of viewing life from his point of view alone, he now understands the way that people's different journeys can interfere with each other. In other words, he learns how to see that life is about the entire community of people who are all wrestling together against life's sometimes unfathomable challenges. The movie is ironically not one of those "Happily ever after" stories like the title might imply.
