Variance/serious question: what is love, does it exist?

[EricW]

Hey guys,

I have a lot of time on my hands so often, I just sit around and think. My most recent topic has been the notion of "love." What exactly is love? Does it exist? Are humans the only species who can experience love because of our relatively advanced brains?

The thing is, I don't really understand what it is. Is love something that only occurs when it is mutual? Well how can that be the case when people "fall in love" all the time but the person whom they are in "love" with doesn't reciprocate the same feelings? Well if love can be just one sided, does it mean that love is just a state of extreme infatuation? Moreover, how do people fall out of love?

Have any of you been in love? How does it feel? Serious answers please.