Possibly the worst emotion ever felt. Makes you feel unbelievably sad, and nothing, not even chocolate can make you happier. It also sucks that you try to get over them, but you can't get your mind off them. It's especially harder when they are one of your good friends and they tell you who they like.
Susie has an unrequited love for Thomas. Susie is Thomas' good friend. Susie likes/loves Thomas. Thomas likes someone else. Susie still talks to Thomas even though deep down inside, she still likes/loves him.