It's a feeling most humans need in order to live a sane life. Without company, you will slowly deteriorate into a mess of hallucinations, that's why prisoners go into solitary confinement. When away from people you slowly go insane and start to crave it. Your mind will go as far as to create a fake person just to keep some of your insanity. That is the reason most people who are trapped somewhere alone speak to air. Well anyway, this relates to love in a sense that we crave it in order to live, it's like a void that needs to be filled. It's for mental stability.