You need to make sure you're going exactly where your guy goes in press coverage. In zone, you can read the quarterback and his eyes a bit to determine where he's going. You don't get the opportunity in press coverage to read the quarterback, so it's all on you.
You take a bunch of people who don't seem any different from you and me, but when you add them all together you get this sort of huge raving maniac with national borders and an anthem.