13 Biggest Avengers: Infinity War Mysteries

In Thor, we were briefly shown a glimpse of an Infinity Gauntlet in Odin's vault, leading to all sorts of shenanigans when a second gauntlet appeared at the end of Age Of Ultron. Kevin Feige said there were two, then it was later retrospectively announced that one was fake (presumably the one with the stones in Asgard), but that doesn't answer the biggest question.

Hopefully Infinity War will attempt to address how it was that a supreme being as powerful as Odin was duped into thinking that he had the Gauntlet (and its Stones) in his vault, or if he was actually in on the deception, and why that would ever be the case. His own Warriors Three are aware that keeping Infinity Stones together is foolish (they say as much in the Thor: The Dark World post-credits scene), so clearly they at least must be aware that the artefact in the vault is fake.

So what's the story? Did Odin show it off to his people and lock it away as an act of false security? Did he remove it from an enemy who believed they had the real one? Or was he genuinely taken in by the deception? It's all very odd.