Sam Wilson's reluctance to take on the mantle of Captain America has been a topic of heated debate both within The Falcon and the Winter Soldier and outside of it, with fans excited to see him take on the shield and become the new Captain America, but Sam himself at first unwilling to take on the mantle.
It's a reluctance best realised by his conversation with Isaiah Bradley about what the shield, and consequently the ideal of Captain America, means to Black people living in the United States. Isaiah Bradley did everything Steve Rogers did, but instead of public adoration and reverence, he was sentenced to 30 years in prison at the hands of his government.
On Sam's end, the American government was eager to accept his reluctance as an excuse to push him aside for John Walker to become their own brand new, blond, blue-eyed and decidedly white Captain America, one that was obedient to the military in all the ways Steve Rogers never was.
The events of the series, as well as the history both within the Marvel universe and the real world, all point to why Isaiah's bitterness is justified, and why Sam's decision not to take on such an enormous responsibility was fair for a man having to take on more expectations than Steve ever could - even if he felt like he was running away, as he told his sister.
In contrast, however, in the most recent episode, Sarah encourages Sam, telling him she never felt like he was running away, taking pride in and trusting him as a brother and hero. His nephews playing with the shield without any fear shows some hope for the future that Sam himself might not entirely feel.
In the end, with these two disparate views to consider, Sam is able to talk it out with Bucky while they train with the shield together. Their talk, despite it centering on Bucky's mental state and recovery, isn't just for Bucky's sake, but for himself as well.
"You gotta stop looking to other people to tell you who you are."
Sam is able to preserve his history by taking time to think, restoring the boat with the help of his community and Bucky as his partner. At the same time, he's able to look to the future, and decide for himself what he wants to do. Once he realises what decision he wants to make, he fully commits himself to training with the shield, readying himself to take on its responsibilities, one way or another.