2009 Saints went 13-0 before losing to Dallas and the Buccaneer consecutively.
2009 Colts went 14-0 before losing to the Jets and Bills consecutively.
2005 Colts 13-0 before losing to the Chargers and Seahawks consecutively
1998 Broncos 13-0 before losing the Giants and Dolphins consecutively.
The Packers are shell shock, even though they won't admit it, will still have that loss stinging in their head. It will hard for them to take the Bears seriously, especially if the 49er's loses today.