Now let's bring the analogy home: If you come up with a story, and you share that story with someone - in a book, movie, song, or whatever means you use to share it - you've given up ownership of that story. The moment it hits the other person's head, they can do whatever they want with it, because it's theirs just as validly as it is yours, now. Likewise, if they are able to come up with the same story independently, your story was not unique enough to be considered "yours."
Good points; to add to this, there is nothing new under the sun. Any story anyone could tell today will be inspired by the same actions which were the basis of all stories ever told--that is, life itself. To copyright a story is to imply you hold ownership of life events. Plus, considering that all western music use the exact same schemes for writing any song (scales, from keys, from notes, which someone figured out if you take these exact increments between sounds you can make something sound pleasant,) it's pretentious to copyright anything which stems from this invention; heck, if copyright existed then, someone would still be making royalties from every song ever to exist.
However, it's odd when it comes to capitlaism; when someone owns a copyright to a creation, it's implied they're the only ones who can control who gets paid for any money earned from the creation. So would writers, artists, and musicians still be able to pursue their craft with the hopes of payment? Or would they be subject to charity, or seeking other forms of employment?