A line of dialogue from Rocket Raccoon in Guardians of the Galaxy warned of the mistake that Star-Lord would go on to make in Avengers: Infinity War. Both Rocket and Star-Lord, aka Peter Quill, were introduced in the 2014 movie written and directed by James Gunn. The two characters returned for another team mission in Guardians of the Galaxy Vol. 2 in 2017 before joining other members of the Marvel Cinematic Universe for Infinity War the following year. Here's what Rocket warned and how it came into play in one of the most talked-about moments in MCU history.

Aside from Groot, Rocket lived his life as a bit of a loner before teaming up with Quill, Gamora, and Drax in Guardians of the Galaxy. The genetically modified raccoon worked as a bounty hunter and mercenary with his focus set on the rewards. Rocket had a brash personality and a sick sense of humor due to the fact that he closed himself off emotionally for so many years. That started to change in the presence of his new acquaintances but he never fully let go of his cynicism.

Related: Marvel Theory: Guardians of the Galaxy 3 Will Kill Off Rocket

During Guardians of the Galaxy, Drax selfishly faced off with an entire army by himself to avenge the death of his family. In doing so, Quill and Gamora were captured and Ronan the Accuser obtained the Power Stone. Rocket was furious with Drax, berating him, and mocking the death of his wife and child before warning of a situation linked to Quill as pointed out by a fan (via Reddit). The scene featured Rocket proclaiming that "everybody's got dead people...it's no excuse to get everybody else dead along the way." His line was meant to prove that avenging his past losses were no excuse for getting more people killed. That same incident would go on to mirror a mistake by Quill when his rage allowed Thanos to move forward with the infamous decimation of humanity.

After the Guardians of the Galaxy rescued Thor in Infinity War, the group went to Knowhere in search of the Reality Stone. Thanos already had obtained the stone and kidnapped his daughter, Gamora, before fleeing. While Quill and a few other members of the Guardians travel to Thanos' homeworld of Titan, Thanos sacrificed his daughter on Vormir to acquire the Soul Stone. Quill, now in the presence of Tony Stark, Peter Parker, and Dr. Stephen Strange, encountered Thanos once again. The group tried to carry through with a plan to remove the Infinity Gauntlet from his hand. They almost succeed until Quill learned of Gamora's death.

Since he cared deeply for Gamora, Quill was overcome with emotion. Instead of carrying through with the plan, Quill attacked Thanos, giving the Mad Titan a chance to break free. He then obtained the Soul Stone before traveling to Wakanda where he got a hold of the final Infinity Stone, allowing him to disintegrate half of all life with the snap of his fingers.

Just as Rocket told Drax, the death of past loved ones was no reason to selflessly put others at risk. Many viewers, and fellow MCU characters, pointed at Quill's reaction as a major misstep that allowed Thanos to kill a big portion of the population. Every member who fought against Thanos lost someone close to them. Coincidentally enough, Rocket survived the Snap whereas Drax and Quill both turned into dust. Drax may have learned his lesson but Quill could have benefited from hearing Rocket's warning in Guardians of the Galaxy years prior.

Next: MCU: How & Why Thanos Looks Different In Each Movie

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