You think you know some stuff about the NFL, and then they play the games and you find out you were wrong about a ton of it.
Just look at Sunday, the final regular-season day of the 2021 season. The Colts looked like a shoo-in for the playoffs. All they had to do was win at lowly Jacksonville. The Jaguars had nothing to play for and had looked lifeless for months. The Jaguars beat the Colts 26-11.
The Steelers had some of the worst-looking losses in the league in November and December, and Ben Roethlisberger's retirement tour had already begun.