10 MCU Plot Holes That Aren't Actually Plot Holes
2. Tony Is Iron Man Again, Despite Retiring In Iron Man 3 - Avengers: Age Of Ultron
At the end of Iron Man 3, Tony gives a speech about not needing his Iron Man armour, and how it was just a "cocoon", and can be seen having the shrapnel (and arc reactor) removed from his chest.
Tony's line "and now, I'm a changed man" made it seem like he was moving on from his Iron Man days and focusing on helping the world as Tony Stark, and not as a vigilante hero.
And then, Avengers: Age Of Ultron opened, and Tony was back in the suit, kicking Hydra's ass and infiltrating one of their secure bases. The ending of Iron Man 3 was never addressed, so what happened? Didn't Tony stop being Iron Man in his last movie?
People who raise this issue always remember the line about the cocoon and Tony being a changed man, but they always seem to forget the very last line: "I am Iron Man".
While that could be taken to mean Tony views himself as a hero whether he wears a suit or not, it could also be taken literally. He isn't outright abandoning the suits; his decision to remove the shrapnel and arc reactor is him burying the demons of his past, halting that over-reliance on his armour that plagued him throughout Iron Man 3.
Even if this final speech did mean that Tony wanted to move on from being Iron Man, then Age Of Ultron does continue this story thread. Tony is working on Ultron, a global peacekeeping program that would remove the need for heroes, and while this plan goes wrong, the intent is still there.
Whichever way you spin it, Tony didn't retire at the end of Iron Man 3 - he just grew stronger.