When most people around the Bruins are asked to describe Dougie Hamilton, the thing that comes to mind quickly is how poised the rookie defenseman has been in his short time with the team. But when he scored the first goal of his NHL career last night at 17:56 of the first period, Hamilton looked every bit the 19-year-old kid that he is. After blasting a puck into an empty net on a very effective power play, Hamilton pumped his fist and sprinted happily toward the Bruins bench. “I can’t really describe it. It’s a dream come true for me,” said Hamilton, who had his parents and a group of friends in from the Toronto area for the game. “It was just a lot of excitement. I couldn’t stop smiling I guess till the second period started. I was shaking, too, from all the adrenaline. It was just a lot of fun and I’m happy I got to do it in front of a lot friends and family.” Following the goal, Milan Lucic fished out the puck for Hamilton. “I was thinking about getting it myself, but he got it for me. It doesn’t really matter,” Hamilton said. He also assisted on Rich Peverley’s second-period goal when his intentionally wide shot hit the bottom of the end boards and bounced over the net to Peverley. “It was pretty lucky. I just tried to bank it off the boards and got lucky that it went over the net. We had a laugh from that,” said Hamilton, who’d gone a half-dozen games without a point. For coach Claude Julien, it was one of the few bright spots in an otherwise frustrating night that ended with a 4-2 loss to the Sabres.