I realize that I don't know what earthly love is like. What does it mean to love someone?

Someone told me the other day, that the world's idea of love is so selfish: "I love you because you make me happy."

I've always used that as a reason for why I loved someone, I even used that as a compliment. Except it's not a compliment, it's not a good reason. It's selfish, it says you love someone for what they do for you.

And when that person doesn't make you happy anymore, you don't love them anymore.

I don't think I know what love is anymore, at least not earthly love.