I've always loved this quote

Love is a temporary madness; it erupts like a volcano and then subsides. And when it subsides you have to make a decision. You have to work out whether your roots have so entwined together that is is inconceivable that you should ever part. Because this is what love is. Love is not breathlessness, it is not excitement, and it is not the promulgation of external passion. That is just being "in love", which any fool can do. Love itself is what is left over when being in love has burned away, and this is both an art and a fortunate accident. Those who truly love have roots that grow toward each other underground, and when all the pretty blossoms have fallen from their branches, they find that they are one tree and not two. -Captain Corelli's Mandolin by Louis de Berniers