It's a very human, relatable thing.
Bucky has proven his fighting ability against creditable fighters such as Black Widow, Sin, Crossbones, Batroc the Leaper, Wolverine and more.
This ability enabled him to survive the normally fatal fall from.
But a couple of years later, when Thanos intends to invade Earth and harm his friends during Infinity War, Bucky does not refuse the.
Sin begins to shoot him and Bucky blocks the bullets with his shield.
When Barnes turned around to suggest their group go out dancing, he saw that Rogers had walked away from the group to try and enlist in the army yet again, despite Barnes' many previous objections.
Bucky has shown signs of aggression whilst depressed and has also redeveloped a relationship with Black Widow.