Avengers: Infinity War - 13 Previous MCU Scenes It Completely Changed

5. Hawkeye's Unretirement - Captain America: Civil War

Strictly speaking, Hawkeye has retired from active duty more than once. In the wake of Quicksilver's death, he rethought his Avengers duty (having already expressed concerns because of his family's fears for him) and hung up his bow and arrows. Then he was coerced out of retirement to rescue Scarlet Witch in Civil War and became part of the mission to stop Helmut Zemo.

He then retired again - as established by Infinity War - because of his family once more, taking a deal to go under house arrest for their sake rather than going on the run like Cap, Falcon and Black Widow. But it compromises his character somewhat for him not to respond when the world is invaded.

Hawkeye is the kind of character who will put his duties as a hero above his own concerns, as already established, and while his family are a paramount concern, there is NO way he'd sit back when he'd already answered the call for a far less serious mission in Civil War. In hindsight, it just looks like he wanted to not be retired when he came back in Civil War because he didn't have the incentive of a government-issued ankle tag.