I thought of it as the long alley is life and the scars are from the experiences of it, but the white cat is usually revered as angelic or lucky, so if it has scars then it isn't exactly perfect and no matter how much you try everyone gets hurt at least once. So that's how i thought of it, but didn't want to say it that way and you could come up with your own meaning that's what poems are about in a sense, to find your own meaning.