There is little doubt that the Marvel Cinematic Universe is littered with several references and Easter Eggs that would eventually prove to be important in other films. Such is the case with Rocket Raccoon's angry declaration in Guardians of the Galaxy which would end up being a forecast of what will happen to Star-Lord in Avengers: Endgame.
It's no secret that both Rocket, Star-Lord, and the rest of the Guardians didn't get along right away when they met in the 2014 movie. However, they eventually learned to work together and accept each others' differences. Still, it's important to note that it wasn't easy for them. For instance, one of them made a huge mistake that would cost a lot for the rest of the team.
In Guardians of the Galaxy, Drax decided to single-handedly go up against Ronan the Accuser to avenge the death of his wife and daughter. Unfortunately, this only led to his defeat as well as the capture of Gamora and Star-Lord. To make matters worse, Ronan managed to get his hands on the Power Stone.
Not surprisingly, Rocket was enraged with Drax's selfish moves but as one fan had pointed out on Reddit, it also led to a line that would mirror what happens in Infinity War. "Everybody's got dead people...it's no excuse to get everybody else dead along the way," Rocket roared at Drax. Interestingly, the same thing would eventually happen in the third Avengers film as Peter Quill tried to kill Thanos for sacrificing Gamora just to get the Soul Stone.
Of course, Peter was not there when Rocket said that line but still, those words would become proof that revenge is not the best way to win a battle.