By Chris Mannix Tatum showed all signs of reaching for the league’s crown(s) this season with 35 points to carry the Celtics on opening night. BOSTON – Throughout the summer, many in Jayson Tatum’s orbit noticed something similar: He’s different. For years, Tatum had been obsessed with individual improvements—become a better scorer, rebounder and playmaker. He talked about All-NBA nods and winning MVPs, molding his superior talent into the NBA’s best. Yet coming off his first NBA Finals appearance, those close to him observed something new. Individual accolades didn’t come up as often. Winning…