When the first overall selection was announced at the NHL entry draft in June of 1997, he hugged his family and then walked to the stage at the Civic Arena in Pittsburgh. Back home in Boston, the FleetCenter Jumbotron carried it live with fans cheering and screaming for the then 17-year-old who was going to be the next big thing for the Bruins.

Five years later, center Joe Thornton -- now 22 -- has come a long way from the giggling, gangly teenager with the nickname "Big Bird," because of his big mane of curly blonde hair.

Thornton, who is one of the league's scoring leaders, will celebrate his arrival to the NHL's elite circle when he participates in his first All-Star game this weekend.

The kid is not a kid any longer. When he first broke into the league as an 18-year-old, he thought nothing of eating honey-dipped donuts while riding the exercise bike. Lunch was pepperoni pizza followed down the hatch by lots of soda. In terms of training, the weight room was a foreign land.

Thornton now is, if not an expert on nutrition, free of his teenage eating habits and he trains hard in the offseason. He has transformed from a rookie just happy to be where he was to a player in the beginning of his prime who is playing with a purpose.

"He's really matured on and off the ice," said veteran goaltender Byron Dafoe. "Off the ice, he's 22 years old now. He's not an 18-year-old kid all starry eyed. Of course, on the ice, he plays with more authority. He seems to take it more into his own hands. He expects to do the job. He wants the puck as opposed to just making a good play or a safe play. That comes with age and experience. Five years in the NHL, even though he's only 22 years old, he's an experienced guy. No one ever questioned his ability or his talent. Now, it's been thrust to the forefront on this team."

Dafoe said he believes that the Bruins' handling of Thornton when he was first breaking into the league is a big part of the reason he's where he's at now in terms of development. His first NHL coach -- Pat Burns -- brought him along slowly.

"I think Burnsie did a great job with him his first year," said Dafoe. "He scratched him a lot, he put him in limited roles like on the fourth line and in doing that, it took pressure off him because he wasn't on the power play or on the No. 1 line and expected to get all these points. So, he got a feel for the league as an 18-year-old and his second year his ice time was increased and his role was increased. Then, even last year, Mike Keenan challenged him from the outset and Joe responded."

When Jason Allison was a contract holdout last fall, the question was raised often whether Thornton was ready to make the jump to the top pivotman. Dafoe said his teammates definitely believed in him.

"I don't think there was ever a doubt," said Dafoe. "It was just that the ability of Jason Allison was so high, could Joe get to that level? Of course, he could be the No. 1 guy on our team but could he match Jason's level? He's definitely responded. They're two completely different players but I think Joe has exceeded a lot of people's expectations and he's only going to get better, that's the scary thing."

One player who knows Thornton well is left wing Sergei Samsonov. Samsonov helped Thornton tremendously when he was picked No. 8 overall by Boston in the same draft. Because Samsonov was more advanced than Thornton, having played in the International League for Detroit, he received a lion's share of the attention. Instead of the spotlight being totally on Thornton, Samsonov absorbed a lot of it, which further toned down the pressure on the teen-ager.

"From his first year to where he is right now, he's become an all-around player," said Samsonov. "Every time he's on the ice, he's a threat. There are some times when I don't think people can stop him. I think they're realizing more and more that Joe is becoming a pretty powerful forward."

Samsonov said both of them have benefited from the experience and knowledge of the older teammates who came before them.

"We've both been around a lot of players who are veterans," said Samsonov. "We picked up a lot of stuff from guys like Ray Bourque and Don Sweeney and the list goes on and on. You start hanging out with those guys and you learn in a hurry. I think Joe's becoming more serious. He's really focused on his game and he's preparing himself well. He hasn't been put in this position until this year. Who knows? If he had been made the first centerman maybe he would've been ready last year. He's really stepped it up this year. He's playing great. The first season is tough for everybody. It's a learning experience and it's a long season.

"But it's not a surprise he's one of the leaders in the NHL in scoring. He's just going to get better and better."

Nancy Marrapese-Burrell of the Boston Globe is a regular contributor to ESPN.com.