I forgot where I found the research, I think in Scientific American a few years back, that the "in love" feeling we get when we meet someone attractive, is simply the release of pheremones in respnse to the pheremones of the other person. To me this would signify health in itself. In healthy people, you'd think that, as a healthy individual, you would react to pheremones of someone healthy, and valid for eventual baby making. I tend to be very intuitive by nature, so I would assume if I mean someone, and the sparks go off, it means they are fit for eventual breeding(not that I think in those exact terms at the time).
You can't suck all the fun out of "love" by trying to constantly categorizing and classifying every single reaction, but it's important to understand these underlying physiological processes and biochemical responses, and how they really work when trying to find someone suitable for a long term relationship.