It’s safe to say that Paul Pierce regrets his decision to bet on his former team. Pierce, 47, made good on his promise to undergo an hourslong walk to work in his robe after being wrong about his prediction that the Celtics would take Game 2 over the Knicks on Wednesday. He said there’s one thing he’s never doing again. “I ain’t never putting a bet on something like this ever again,” Pierce said on Instagram live upon finally arriving in the Fox parking lot. “I feel like I accomplished something crazy at the end of the day.”