At one point in Sunday's playoff opener at Oracle Arena, Stephen Curry waved his arms to exhort the crowd. Do Warriors fans, numbed by three seasons of relentless winning, need exhortation? Oracle ultimately became loud — very loud — in the fourth quarter of Golden State's 121-109 victory over Portland. Green, in his postgame news conference, made a point of praising the crowd for helping the Warriors weather a first-half barrage from Blazers guards CJ McCollum and Damian Lillard. [...] it's fair to wonder if Warriors fans have become complacent given the team's historic run — 207 regular-season wins the past three years, an NBA title in 2015 and a Finals appearance last year. Chronicle columnist Bruce Jenkins raised the question over the weekend, linking the phenomenon with the near-inevitability of Warriors wins at home. There were isolated outbursts of rollicking noise in the first half, such as when Curry made his first three-pointer and when JaVale McGee blocked Lillard's attempted dunk. [...] it was difficult for Warriors fans to sustain, mostly because their team couldn't gain any separation from the Blazers. [...] midway through the third quarter, Green's...