Coltman (24) is set to play his 50th game for Otago this Saturday, when the blue and golds take on Bay of Plenty at Tauranga.
The hooker said it had all gone pretty quickly since he made his debut for the province in the first game of 2010.
But it had been a great ride.
''I love it. I really do. You just get out there with all your mates, playing with all the boys, and playing the game you love,'' he said.
''Not many people get the chance to play something that they really like doing, every day.''
The bushy bearded Coltman made his debut against Counties-Manukau when he came on to replace Peter Mirrielees at Pukekohe when Otago was well beaten.
''I can remember that game quite well. Tana Umaga was still playing for Counties and it was a whole new level to adjust to,'' he said.
''It was a tough introduction. I had only played [under] 20s and before that, club, so it was all pretty new to me.''
Otago did not have great year in 2010, Coltman played six games all season for Otago as the side won only two games and ended up bottom of the table.
''It was a pretty rough season all right. We only won two games.''
But slowly Otago improved and with Tony Brown and Phil Young coming on board in 2012, Coltman said it had been a great past couple of years.
''We made the final in 2012, then we had the successful shield challenge last year and making the semis that same year.
''They [Brown and Young] are just such good guys to work with. Good coaches, guys who really know the game and the way they want to play the game.''
Coltman comes from Taranaki and came down here to study physical education at the University of Otago but still has to finish his degree as rugby got in the way.
He has played every game for Otago since 2011 - on a run of 43 consecutive games - flirting for a period as a tighthead prop in 2012.
The Alhambra-Union man has got bigger since his debut, putting on 10kg, now up to 115kg but needs that bulk to survive the knocks.
Coltman looked to be on the inside track for the All Blacks this season after joining as an ''apprentice'' last year.
But he had an up-and-down season with the Highlanders and did not receive the call from All Black coach Steve Hansen.
Coltman said it was not something worth worrying about and he has not heard from Hansen and co.
''You've just got to stay in the here and now. Just keep playing tough and playing as well as I can. I went all right at the camps. The door is not closed. What happens, will happen.''
Throwing in was a constant focus on Coltman. He said he worked hard on that skill but it was not easy. The focus on the public for a hooker was finding the jumpers in a lineout.
''The public think that is all it is about. And it is a big role and you have to get it right. But the scrums are a key part of it. Working hard around the field. Carrying the ball, making your tackles.''
Coltman has had his family alongside him for the ride and his parents and brother will be at the game in Tauranga on Saturday.
And as for that bushy beard ?
''I just don't like shaving. I gave it a bit of a clip back in June and I'll do it again at the end of this season.
''It is something not worth worrying about.''
