I think the closest thing I can come to defining what that vital thing is for me - is that there's a sort of soul-quality in writing, if it's any good. It has a spirit or an energy to it that is very integral to who the writer is on a deep level. It's almost a cellular thing. It takes place in the cells of the writing, and it is what makes it alive or not.
Paris is particularly beautiful in the rain. It was just a nice experience for me, a pleasant experience, and I was able to present it to the world through my eyes, very subjectively - not realistically, but subjectively.