system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] Why didn't Bucky get his arm back sooner from Black Panther?

I'm sure it would have been handy to have. Bucky looked like he was helping with chores around, why wait until trouble was brewing before giving him a hand?
gpt
The clear implication is that Bucky didn’t want an arm which was a reminder of his decades of being a programmed killer. 

Consider that in Infinity War, when T’Challa brings the new arm, he doesn’t have to say anything. Bucky understands immediately that he’s got to give up his peaceful interlude and fight again.