Most Helpful Guy
This is my view of it.
Romantic love is based mostly in attraction, lust and desire. It's all about emotion. You often crave to get this love in return also. This "love" can turn into hatred really fast.
When the attraction is gone then more times than not, so is also the love. One may then question if there was any love to begin with.
Unconditional love is what I call the "mature" or "real" love that is more of a state of being rather than just emotion. In this state you embody traits such as stillness, clarity and freedom (of mind).
There is no craving in this state of being. You don't "want" things from other people but you happily accept what is given. You don't love because you want or expect love in return. You instead love simply because love is what you are and love is all you can give.
I'd say that love is also entangled with wisdom. If you knew everything about everyone and everything, you'd not be able to do anything but love. You would then understand that people are really not evil but rather lost and broken.
It's hard to forgive what you can't understand. And it's hard to love what you can't forgive.1