Love by its very definition is going to be different for everyone. For some, it may truly not exist. For others, it might look like something else to us observers, like lust or obsession. Think about how many times we say "that isnt love, its just a teenage crush" etc but I dont think we have any right to do this. If someone says they are in love they have the right to believe that. They will find out, in retrospect if it was true or not.
So, here's my opinion of what love is, to me:
1: You'll know in retrospect usually. It's very hard to tell til you've had some space from the situation - even broken up with them. WE truly do sometimes only realise it wasnt really love when we are free, or look back and realise it *was* love, and we accidently missed it , Oops (maybe we didnt *want* to be in love at the time?)
2: Love is pain, and arguments. Its plenty of good things too, but its not all sweet and fluffy and perfect. That would be unrealistic. You cant know the true stregnth of something til suddenly, its being tested. If you love someone, you care enough to argue, but also care enough to make up and compromise.
3: often love is most present when you are trying to deny it. If you fight it and fight it and really dont want to be in love, but realise you are, that knowledge will have the ring of truth to it, and you wont be able to deny it to yourself forever.
4: you *can* love someone who dosent love you back. I have friends who deny this, and say that then it is lust or obsession. For them, this may be true, for me, it is not.
5: The good stuff finally: you cant stop grinning, you keep having days that are "the best in your life so far". You think about them far too often, but when you do it isnt just lust you feel, but something warmer. You know that if you lost them, you wouldnt die, but the light would go out of your life. You trust them, they make you feel safe. You know you can come to them with your problems and they wont judge you, and visa versa. You feel addicted to their wamrth, the scent of them, the texture of their skin - you're intoxicated by their prescence. You feel imspired to do better things with your life. You feel far more confident, far less scared, of life and situations, because you know there is someone who will be there for you, and listen. They are the one person you would take with you, to a desert island. You imagine the future with them, and it dosent scare you. You stop having a choice. You just know. Loving them is as much a part of you as your hands, your breath, your heart.