Dak Prescott turns 29 on Friday, July 29. The symmetry is not lost on him as he enters his seventh season as Dallas Cowboys quarterback. He will take a moment and look back and reflect because it’s an opportunity to take stock in where he came from and reinforce where he wants to go. “It’s a quick reflection,” Prescott said. “But it’s definitely moving forward. As they say, the rearview mirror is a whole lot smaller than the front windshield. “I think it’s good to do that. I will be 29 on the 29th. It will be the golden birthday so I plan for this to be the golden year.” Nothing would be more …