Helmut Zemo, the main antagonist of Captain America 3: Civil War, shows a rather odd level of knowledge about HYDRA operations throughout the movie.
For example, he seems to know a lot about the Winter Soldier program and UN security protocols, including:
That there's a code book to control Bucky, who has it, that Barnes did "something bad" in 1991, and how to impersonate the UN shrink.
He intends is to use this knowledge against the Avengers, and he clearly has enough information to formulate a complex and involved plan.
However, he also seems to be missing a lot of details, including the key facts of:
where the Winter Soldier base is, and what Barnes actually did on that day.
Is there any explanation how Zemo, who otherwise shows no indication of being anyone special or unusual, came into all of this knowledge.