When do you know that you're in love?

You just know. If you have to ask yourself, then you aren't in love yet. Don't take love lightly- it only comes after a lot of effort and patience in a relationship. There is a huge difference between a big crush and being in love. When you are in love, yes- you will do anything for that person. But I would do anything for my best girl friend, and I am not in love with her. There's a difference between caring and loving. Love is unexplainable and you can only understand when it hits you. But it is definitely not something you question, and it doesn't come with every relationship.