10. Cap Didn't Lift Mjolnir To Spare Thor's Feelings - Avengers: Age Of Ultron
One of the MCU's most enduring mysteries has been whether or not Captain America (Chris Evans) was actually able to lift Thor's (Chris Hemsworth) hammer Mjolnir or not during Avengers: Age of Ultron's party scene.
Though we of course saw Cap finally wield Mjolnir in Avengers: Endgame, fans continue to debate whether Cap truly was worthy back in 2015, given that he was shown slightly shifting the hammer when he attempted to lift it (much to Thor's distress).
But the film's writer-director himself, Joss Whedon, offered up his own theory to a fan who asked him for an answer, telling them, "Did he fail? Or did he stop?"
Given that Mjolnir doesn't work in degrees of worthiness - you can either lift it or you can't - the implication of Whedon's statement is clear, that Cap purposefully feigned an inability to lift Mjolnor in order to spare his pal Thor's feelings.
When Thanos (Josh Brolin) was on the warpath in Endgame, though, there was no time for such modesty, and Cap finally got to wield the magical hammer - this time, much to Thor's relief.