As actual Love is a choice, and not an emotion, and it is definable as the choice to do what is best for someone, and put them first, even at a cost to yourself. Then it is easy to see that the most natural state of human existence, is one in which we love someone, put simply, we end up loving people, because the initial motive for our very creation, is love in itself.
Usually, we fall in love with a person that we deem attractive and suitable for us, but also a person who shows that they are attracted to us. We all love the feeling of being loved and having someone who cares. Without love, even parental love, you may end up living in a miserable life.