The Hobbit - Chapter 04 - Over Hill and Under Hill

[Aiwendil]

This second adventure for Bilbo and the Dwarves is altogether more serious than their first. If the trolls perhaps come across as overgrown Cockney types, the goblins seem to be much more sinister and "realistic" villains.

I can’t help but wonder how the goblins remember the swords Glamdring and Orcrist; is there some sort of collective memory or are they so long-lived that they would actually have experienced those weapons previously?

This is an interesting question. If Orcs are indeed corrupted Elves, then (as others have suggested elsewhere) it seems reasonable to suppose that they are immortal. On the other hand, there is a way in which immortality simply doesn't seem to fit with their portrayal. But I imagine that Glamdring and Orcrist were quite famous among goblins; it doesn't seem any stranger that the Great Goblin would recognize them than that Legolas or Aragorn would recognize a Balrog.