DJ Holloway at 2012-08-27 15:27:52:
The theme is the suggested meaning of a text beyond its explicit elements (plot, character, etc.) It is more than a concept, it should be a commentary on the concept. So "love" is not a theme, but "love conquers all," "love is everywhere," "true love is a lie" are all themes.
Themes are also not specific to the film/story, rather they are taken from the text and could apply to humanity as a whole. Staying on the "love" tip, the theme of Titanic can't be "Rose's love for Jack goes on" because that only applies to them. Instead, it's "love goes on," which can apply to all of us.