Johnny Knox's life changed dramatically when he took a devastating hit in December 2011. Fourteen months later, Knox realizes that his NFL career is over. "As an athlete, you don't want to give up, you want to keep on fighting. That's how I've always been," Knox told Sean Jensen of the Chicago Sun-Times. "But it's been on my heart for a while. I know how my body feels, and I know I'm not going to be the same and perform at the ability that I used to. "So I'm moving on and going forward."