Middle Earth itself has been described as the "ring" that Morgoth poured his own power into. Since a river is an extension of Middle Earth, it means Morgoth really was the true Lord of the Rings.
He conquered the kings of men, and turned the dwarf lords to greed and wrath. He built Barad-dur and obliterated Numenor. He caused the separation of Valinor from the rest of Arda. He killed Gil-Galad and Elendil, and triggered the Elves leaving Arda forever.
If not for the hobbits, Sauron would have been unstoppable.
If your only source is the movies, one of the annoying gripes about them is they have this deceptive editing that makes it seem like Frodo left the Shire within a relatively short timespan after the birthday party.
Frodo got the ring on the 22nd of September of 3001. He leaves Bag End on the 23rd of September...of 3018.
Interesting, though that still doesn't explain the aging part though. I get that Hobbits age slower than humans but if their life expectancy is only 100 years, the difference should be noticeable right?
I would watch this again and again and treasure it and call it my precious FOREVER.
The movie could be a long story arc with the main fish getting the ring stuck around them and having all sorts of adventures, learning valuable lessons and finally returning to their spawning point to teach the other local fish all the knowledge the main fish had learned. It would all wrap up to this beautifully happy ending and BAM! Déagol grabs it. Movie ends.