system
Given the following post, respond as if you're commenting on Reddit:
human
[Tolkien] Wait, wasn't Gollum a Hobbit?

In "The Hobbit" Gollum at one point wonders aloud "what is a hobbit?", but it was also shown in "Return of the King" that Gollum recieved the one ring from a friend as his birthday present, and he seemed to be a hobbit at that point.

Is there a good reason why he doesn't seem to remember Hobbits when he first meets Bilbo?  His unnaturally long life caused him to forget what he once was?
gpt
Gollum is a descendant of the Stoors. There used to be three tribes of Hobbits, the Stoors, the Fallohides, and the Harfoots, who lived in different regions and were somewhat different both physically culturally. Distinct ancestors of the Hobbits we all know.

The three groups gradually became one when they settled in the Shire. The Hobbits of the Third Age are descendants of all three tribes, although the Brandybucks and the Tooks are closer to the Stoors, and the rest of the Shire seems closer to the Harfoots.

Anyway, Gollum is a descendant of the Stoors who did not settle in the Shire, settling instead in Gladden Fields.