Love?

What's the difference between love and being in love? I had someone tell me that she loved someone but didn't know if she was in love with him. Then I wondered: what's the difference? Is there a difference? There's platonic love, and brotherly love, but as far as romantic love is concerned, is there a difference between love and in love? In my logical frame of thinking, I would say that the difference is that if you're "in love," both people feel the same way. I think that the language of it implies that there is a mutual feeling, a symbiotic sort of something. Clearly, as the love expert, I'm going to say that's the difference, at least from a logical point of view.

So what's the deal with that? Can you be in love with someone who doesn't love you back? Can you have romantic love feelings for someone and not be "in love" with them?

There's a song that says "the greatest thing you'll ever learn is just to love and be loved in return," and I think that's probably true. So is it harder to love or be loved? I find it pretty easy to love people, and maybe harder to be loved. But is that because I don't want to be loved or because no one loves me?

It's so hard to be scientific and examine situations like this when you don't have the proper variables. It's totally impeding my research.