Iannis says in Captain Correlli's Mandolin, the movie (probably the book too, which is forty million times better than the film) this. I thought it was nice.

When you fall in love, it is a temporary madness. It erupts like an earthquake, and then it subsides. And when it subsides, you have to make a decision. You have to work out whether your rootsb have become so entwined together that it is inconceivable that you should ever part. Because this is what love is. Love is not breathlessness, it is not excitement, it is not the desire to mate every second of the day. It is not lying awake at night imagining that he is kissing every part of your body. No... don't blush. I am telling you some truths. For that is just being in love; which any of us can convince ourselves we are. Love itself is what is left over, when being in love has burned away. Doesn't sound very exciting, does it? But it is!