For J.R. Smith — actually, for all the Knicks — the 2013-14 season has been a collection of extremes. The team has had ups, downs. Injuries everywhere. A five-game winning streak is followed by a five-game losing streak. For Smith the season began after rehab from knee surgery and a five-game suspension for violating the NBA’s anti-drug policy. There was a fine by the league plus the public blistering and two benchings by coach Mike Woodson for the shoelace nonsense. So Thursday was just a fun night, an utter 117-86 blowout of the hapless Cavs. Smith got a start for the shorthanded Knicks, who were down five bodies, including Iman Shumpert. He brought energy, enthusiasm, points. And fun. Smith felt it was about time. “Without a doubt,” said Smith, who had his 10th straight double-figure scoring game with 19 points, forged on 8-of-16 shooting. “The stuff we went through this season, losing guys. These are the bright spots you want to have, especially playing at home. You’ve got teammates on the bench going crazy, guys on the court excited. … There’s nothing better.” Smith broke quickly from the gate in the small ball lineup. Amid his 11-point first quarter, Smith grabbed attention with a highlight-worthy play at 6:25. Smith crossed-over overmatched rookie Anthony Bennett, beat him to the baseline and threw down a dunk.