You're not in love with someone unless they are in that love with you. Otherwise, you're in love by yourself and just wishing the object of your affection reciprocated.
... the hell ?!?
I've never heard of being in love with someone being something limited to reciprocal love.
+1
Love itself isnt selfish ! Love is THE ONE AND ONLY MOTIVE of humans for altruistic acts !
While that last statement may (or may not) be accurate, you can't possibly argue that people only use the word "love" to describe what is actually love as opposed to using it as a descriptor for far less noble and more selfish feelings. When I hear someone claim they love chocolate, I don't consider the statement to contain anything resembling "altruism."
That said, regarding "I'm in love with ___" vs "I love ___," while I have no official ruling on the topic, I always had the impression that any distinction between the two statements, if any were necessary, would likely be one of distance and knowledge, but not necessarily reciprocation.
You can't be "in love with" Taylor Swift if you don't know her. You can love her, maybe - or at least you might love the
idea of her, the concept you've created as representation of who you believe her to be in your head, but there's no relationship between the two of you on which you can base some claim of love; there is nothing there with which you can be "in love." You can only direct love at the idea, if indeed that is what you are feeling.
You could, however, be in love with Taylor Swift's music. That's a tangible, concrete thing with which you can interact, even if it isn't a sentient entity that has the capacity to love you back.
*shrug* Like I said, nothing resembling official definitions there, just how the two phrases work in my head.