*Spoiler Warning: You are being warned that this article contains major spoiler about Avengers Endgame so if you don’t want to get spoiled do not read ahead.
So even though Avengers Endgame wrapped up pretty up everything in its final act and didn’t leave a loose end that viewer could nitpick in the end. However, there was one thing that the viewers were unable to understand in the post-credit scene.
The scene we are talking about is that an old Captain America sitting on a bench. When Captain America is given the task of returning back all the infinity stones in their respective timelines. They have to do this because Ancient one explains to Professor Hulk if Infinity stones are removed from their respective timeline those timelines will split off in alternate dark timelines which will be easily susceptibles to the effects of dark energy. And therefore Professor Hulk decided that after they are done with defeating Thanos they have to return the infinity stone back where to take them from.
So the mind stone and time stone were taken from New York during the event of Avenger 1. The reality stone was taken from Asgard during the event of Thor 2 the dark world. The Power Stone was taken from Peter Quill During the event of Guardian of the Galaxy 1 and the Space Stone was taken from the Shield Base After the end of WW2, Sometime after the events of Captain America The First Avenger. Captain America is tasked with returning all the stone to their respective timeline along with Thor’s Mjolnir which he took from young Thor.
But Professor Hulk sends Captain America through the Quantum Tunnel he doesn’t return back. Professor Hulk, Bucky, and Falcon think that there is something wrong with the Machine. However, when Bucky looks to the side he sees and an Old Captain America sitting on the cliff side.
Now Many People Are Wondering why is Captain America is so old in the end scene. Well, the reason behind this is that when Captain America went to return the space stone in the 1940s he decides not to come back and stays there with Peggy Carter to live the life he couldn’t have as he was frozen in ice for 70 years.