I dont think he cares about going out on top. (He already knows that hes on top anyway). I think he just likes to compete and play the game.
His dad said it best (who is a regular on Boston local radio) asked after the Seahawks win he said (this is his dad btw that knows the kid I think pretty well) he said Brady will not ever want to quit. He's like Pete Rose/Brett Favre mentality he will die out there if he has too. He envisioned that Belichick will have to cut him before he quits.
The interviewers further pressed if he went down hill would he retire if he couldn't play at a high level he said he likes everyday the idea of fighting for his job, and playing the game and he would welcome a trade at that point.
This all makes sense too he was a third string QB in college, he was the 4th QB on the Patriots depth chart. The guy has talent, compete, and drive but he also has humility, braveness, and vulnerablity that makes him even more dynamic.
Guys like Peyton think of legacy and going out on top. Brady is in the Favre category where they don't care about stats or any accolades. This is a guy who values spending time with his family and being an inspiration to him. His personality has been characterized as a guy who only has football as his main drive and ambition. He's not a guy who has hobbies or things that he has on the back burner. He's an old throwback to QB's who were about the game. New guys get the endorsements, and have themselves defined by being cool, or being branded.
What will stop him is an injury - simply put. I am old enough to understand people's personalities and even Peyton had lots of pain from his neck, Favre was injury prone at that point. These guys don't go out unless it's an injury.
