One of the bigger head-scratchers in the MCU is why Odin (Anthony Hopkins) had a fully rendered Infinity Gauntlet in his vault on Asgard. We see it during the scene in Thor: Ragnarok when Hela (Cate Blanchett) ventures below the palace with Skurge (Karl Urban) to resurrect an undead army with the Eternal Flame. Skurge voices his amazement at "Odin's treasures" while Hela simply says "FAKE!" and pushes the Gauntlet off its pedestal before declaring that "most of the stuff in here is fake."
But why the hell would the ruler of Asgard and the protector of the Nine Realms even have such a thing in his stash of valuable items when Thanos was presumably the only individual who forcibly commissioned the dwarves of Nidavellir to built a device that could harness the power of all six Infinity Stones? Well, a new Reddit theory by DraftDraw actually has a pretty logical explanation of this, despite the fact that Ragnarok director Taika Waititi doesn't care and thought it would be a fun easter egg that teased the close proximity of Infinity War.
Anyway, the theory posits that when Odin was a warmongering god with Hela at his side, he concocted a plan to rule the universe with the six Infinity Gems. Since he already had the Space Stone (the Tesseract), he and his army were able to easily travel between different worlds and quickly conquer them. During this time, he asked the inhabitants of Nidavellir to devise a device that would allow him to wield and harness the power of all six stones. Working on his orders, they forged a test mold of the gauntlet we eventually see in Ragnarok.
Around this time, Odin might have discovered the whereabouts of the Soul Stone, but when he learned that in order to wield it he'd have to sacrifice the thing he loved most, his daughter Hela, he gave up his conquest of ruling the universe. His change of heart to protect the Nine Realms instead of subjugating them put him into direct conflict with the goddess of death, and he was forced to banish her from Asgard and lock her away in what he hoped would be a permanent exile.
Afterward, he took up the title of Allfather and focused on watching over the Realms while raising his two sons, Thor and Loki. And while Odin covered up the original fresco of his and Hela's conquering in the palace, he placed the Infinity Gauntlet in the vault as a constant reminder of his former actions, what he had given up, and what he had sworn to now protect. When Thanos eventually forces the dwarves to make him a weapon, they already have the blueprint sanctioned by Odin all those centuries ago.
Moreover, the theory also states that Hela might have been banished to Hell via the Space Stone, which would have thrown the universe out of whack, since Hell is not a place for living beings. In an effort to balance things, the universe triggered the Ragnarok prophecy that led to Hela's escape and the ultimate destruction of Asgard.
The most heartbreaking thing of all is summed up by the reaction of Reddit user Universal04:
"This makes things so much better and actually makes Hela a little bit better, I love the fact that Odin changed his mind because he loved Hela and Hela thinks that he betrayed her."
thejonathanjuan took the theory one step further by outlining its possible ripple effect on Avengers 4. While there's a 99.99% chance it's not true, the argument is extremely persuasive and will certainly pump you up for next May.
All in all, DraftDraw's original hypothesis is logically sound, even if no one at Marvel Studios will confirm it. As slowmosloth puts it, the theory is:
"Really good compared to most of the theories posted here. It’s well thought out, not fan servicing, and doesn’t break continuity. The only thing I would say is that it seems unnecessary to explain all this in the movies even if it were true. I would more just accept this as pretty good head canon until proven otherwise."