(some spoilerish but general plot discussion here)
the Hero is a man from a different time and place, and the world has changed without him. he is treated as a symbol of goodness, but his idealism seems antiquated. this leads him to doubt himself, although never his principles.
the military complex adopts him, makes use of his powers, but he later learns that all is not as it seems.
the only person he can trust is his female companion, who is physically weaker but knows more about the world, and so helps him uncover the achilles' heel of the rogue military operation.
his nemesis, with whom he shares a unique shared past, is in many ways his equal in combat, but with the advantage of being completely ruthless.
in the end, the hero triumphs not by destroying the baddie, but by convincing him that their shared history, what they have in common, is more important than their differences.
captain america: the winter soldier is the superman reboot i'd always wanted.