‘Avengers: Endgame’: Robert Downey Jr.’s Most Heart-Wrenching Line Came from the Actor’s Own Life

Avengers: Endgame wasn’t the end of the Marvel Cinematic Universe (MCU). But it did turn out to be the grand exit for Robert Downey Jr.’s Iron Man. Despite the looming possibility of Iron Man 4, Marvel and Downey took the high road in letting Tony Stark go out on his own terms. To that end, it feels only fitting that Downey’s final Avengers line comes from his own life.

‘Avengers: Endgame’ was the final appearance for Iron Man in the MCU

For years, fans wondered how long Downey would stick around the MCU. Since 2008’s Iron Man started the franchise, the actor had become the poster boy for the movies. Yet, Downey’s price tag also rose with each contract negotiation. At some point, the actor and Marvel would have to cut ties. And Avengers: Endgame was the perfect opportunity to do so in epic fashion.

After all, the movie serves as the penultimate — and most climactic — chapter in Marvel’s “Infinity Saga.” Tony Stark needed to play a key role in the Avengers’ defeat of Thanos (Josh Brolin). Some fans believe Downey might return to the MCU sometime soon. But for now, Iron Man gets the chance to be the hero one last time, trading his life for half the universe.

Robert Downey Jr.’s own children came up with the most tragic line

Fans would have always struggled to say goodbye to essentially the main character of the MCU. But making Stark’s death even more tragic was the addition of his young daughter, Morgan H. Stark (Lexi Rabe). Early on, a sweet scene between the two in Avengers: Endgame sets up Tony’s posthumous message to Morgan, namely the now-iconic “I love you 3000.”

But as Downey revealed during a ComicBook.com watch party for the movie with directors Joe and Anthony Russo, the actor suggested the line based on interactions with his own kids.

“It was something that I think Exton, my now-8-year-old, used to say to me, and a lot of kids say, you know? It’s before they can quantify love they just think of the biggest number they know, and it’s usually like 2,000 or 3,000, whatever, and it turned out to be really significant. But all the stuff in this movie was about us really starting to bring our own experience, lo these many years into these characters and the and the epic sojourn.”

As Downey later points out, that single line of dialogue creates a poignant emotional connection for viewers. Without that bedtime scene between Morgan and Tony, his message after his death wouldn’t hit fans nearly as hard. In just two scenes, Avengers: Endgame establishes the father-daughter bond. And it resulted in the most memorable line of the movie.

Will Tony Stark reappear somewhere in the MCU Phase 4?

In fact, Tony’s final on-screen words are so heartfelt that fans are divided over Downey’s potential return. No one truly stays gone in comics, since anything is possible. But for the ongoing MCU, it’s hard to imagine a more powerful exit than the one in Avengers: Endgame. Besides, even if Downey makes an MCU return, it doesn’t have to tarnish his epic death scene.

Black Widow, for instance, proves that Marvel Studios aren’t above hopping around in the timeline. That film already resurrects the title hero from her own Avengers: Endgame death. And in a similar fashion, Downey’s Tony Stark could pop up in flashbacks, another pre-recorded message, or even an alternate timeline. None of those options would undo his sacrifice.