I think this is a song about knowing a relationship is going to end- maybe it was only a summer fling or there's some other circumstance that puts an expiration date on it. In spite of this knowledge though, the speaker wants to enjoy whatever bit of the relationship they can, wants to remember the positive even if it means lying to each other about whats going to happen.
In relation to the movie, it plays during the summer love montage, so I think at that point Zach and Shaun didn't think the relationship was necessarily going to last forever so the song is meant to imply that they still wanted to be happy even if there was a sort of end date attached to their relationship. So, even though the movie was happy in the ending, at the point when the song played there was no guarantee of a happy ending.
I think this is a song about knowing a relationship is going to end- maybe it was only a summer fling or there's some other circumstance that puts an expiration date on it. In spite of this knowledge though, the speaker wants to enjoy whatever bit of the relationship they can, wants to remember the positive even if it means lying to each other about whats going to happen.
In relation to the movie, it plays during the summer love montage, so I think at that point Zach and Shaun didn't think the relationship was necessarily going to last forever so the song is meant to imply that they still wanted to be happy even if there was a sort of end date attached to their relationship. So, even though the movie was happy in the ending, at the point when the song played there was no guarantee of a happy ending.