With the end of the school term yesterday, Mr Simpson (53) finished his teaching career.
"I've always told the kids to make their own opportunities and now I'm taking my own advice," he told the Otago Daily Times.
In April, Mr Simpson and wife Pauline bought Off the Rails, a tourism business offering fully supported tours of the Otago Central Rail Trail.
The couple have two daughters aged 12 and 22.
For the past four years, Mr Simpson has been the principal of South Otago High School, coming to Balclutha in 2008 after nine years at Timaru Boys' High.
Born in Dunedin, Mr Simpson was raised in Dunedin and Christchurch before training as a science teacher, later becoming head of science.
He also taught electronics, before taking on more senior roles as assistant principal, deputy, and finally as a principal.
"If you haven't got the passion for teaching, the kids will know."
With 30 years in the education field, Mr Simpson said he felt it was time for a change.
"This is one of those jobs that is very much a full-time role, with a lot of evening work. The idea of 10 weeks' holiday is a myth. There's no down time."
"I'll miss the contact with people, from the kids right through to the grandparents. I won't miss all the meetings," he said.
"I have to learn a few things about the new job. I'm just young enough to try something new."
While Mr Simpson will often be working from his Naseby holiday home, he and his family have no plans to leave Balclutha.
"I absolutely love Central Otago. It's a great chance to spend time in Central Otago while staying in Balclutha.
We've moved five or six times in the last 30 years - it will be nice to stay settled."
He said he loved the landscape of Otago and preferred to live in smaller cities and towns which offered a semi-rural lifestyle and "the best of both worlds".
Mr Simpson spent the majority of his last day trying to catch up with people.
"I'm not one for farewells, I normally avoid them like the plague. I'm not going far. We're staying in Balclutha and I'll travel to Central a few times a week."
Mr Simpson was farewelled by the school during assembly yesterday morning, with pupils performing a kapa haka, before a staff farewell later in the morning.
A replacement principal for South Otago High School has yet to be announced.
