What is love?

However this is the title of a populat song in the 80's, this is a legitimate question. What actually is love? How can you describe it? Most people can't, we just "know" what it is. But do we actually know something if we can't describe or teach it? Basically, love is a lot like the meaning of life, no one actually knows what it is or how to describe or express it, but we all truly know what it is. Love, like the meaning of life, is completely relative to what you want it to be. However, in Rebecca, I see love as being complete happiness. The characters aren't in love with eachother but they are in love with happiness and use others to obtain that happiness. This is seen completely with the conflict between Rebecca, Maxim, and the narrator. They all love happiness, that is all they want. Rebecca's happiness is power, Maxim's is Manderley, and the narrator's is just having someone to be with. Once these characters start to lose their happiness, they lose love which is actually them losing their meaning to live. The problem is with this book is that to obtain or keep these happinesses, only one character will be able to survive. This is completely due to the fact that each of the characters' happiness is intertwined with another's. So to sum up, there will be one prevailing character at the end to have pure happiness, love, and meaning of life, I believe, but the one problem is who can they share it with? What is all of this if you won't have anyone to share these aspects of life with? Nothing. Thjs will cause the final character to probably kill themselves or run away from everything. These are all assumptions but I'd like to know what other people think. (I am a bit behind in the book also so I could be stating the obvious but I really don't know)