I don't think it's something so easily labelled. I think it's just something you KNOW. I mean, i used to think I'd been in love before and then I actually fell in love with someone and I knew.
I mean, love can be as simple as walking down the street hand in hand or as complex as mind games you play with someone you claim to hate but can't seem to stay away from.
In my case I fell for someone who.. lets just say, wasn't good for me.
But I fell for then regardless and... I don't know. It's like telling yourself that you're giving every part of you that ever was and ever will be to this person.
That all that you are belongs to them and vice versa.
You're telling yourself that this person, whom of which you've gotten to know, is part of you.
They've completed you.
And without them, you'll never feel completely whole.
Because you are one, now.