d.i.v.a. - to me the feelings described by radiogaga could (not always) be just infatuation and are often there in the beginning, fading out as you get to know that person.
leighkaty - the reason you felt like this over the new person was just that - because they were new.
To me, love is more than chemistry, although that would have to be there in the first place. For me, love is a feeling where you know that person better than anyone else. You know their good points and bad - and love them anyway without wanting to change them. It's about feeling so strongly about someone that you're willing to compromise over things you may not have been before. It's almost total trust in someone. It's making yourself vunerable and having that returned. It's about being yourself with that person and not feeling that you have to change to suit them - they love you for who you are too! It's lots of other things too, but for me, that's the gist of it.