Re: Confessions about love, relationships guilt and the world from a young sociopath.
For me, loving someone means that you wish the best for that person (or other species of animal, for that matter), and that you hope for him or her to find contentment and happiness even if that means that you end up losing out somehow. For example, a mother goes hungry so that her child can have something to eat.
The excellent British film, "Separate Lies" deals with just this theme, and I commend it to you if you can find it. If you do, let me know what you make of it.
However, as you rightly point out, love may mean something different to someone else--it is one of those words which defy exact definition. Much easier to say what it is not: not desire, not sexual heat, not need to possess, etc.