Before Jason Kidd stepped foot on an NBA floor as head coach of the Brooklyn Nets, he reached out to Spurs coach Gregg Popovich for advice. “Stay positive,” Kidd recalled Popovich telling him. That may be the best advice Kidd’s received. Every arena Kidd steps in, there are handful of reporters wanting to know why. Why are the Nets, with more than $100 million in payroll, sitting at the bottom of the Eastern Conference? Why does Kidd’s team look disinterested? Why is Jason Kidd, less than a year removed from playing, coaching the Brooklyn Nets, with a roster including Deron Williams, Paul Pierce, and Kevin Garnett. So many questions, so few answers. But here Kidd was, standing outside the visitors’ locker room at the AT&T Center answering questions about his then 10-20 basketball team. One of the questions he was asked: What he’s learned about coaching in the NBA after 30 games. “There’s a lot,” Kidd said. “It’s too long for me to tell you right now.” Kidd said he didn’t have time to dig too much into what he’s learned because he “has a game to coach.” That game: A 113-92 blowout at the hands of the Spurs on Tuesday night.