"I just think I'm so out of context," he says of being celebrity-spotted in Tauranga.
"If you were to sit in a place for 10-15 minutes, people would start to realise. Generally speaking in smaller towns, it takes a little while but once it starts, it starts."
He was born in Scotland, came to New Zealand at age 7, and moved to Australia in 1995.
He's got a bit of an Aussie twang, bit of a Scottish burr. Every now and then, a Kiwi vowel drops in.
Since becoming an actor, he's played a long line of good blokes, which stretches back to Mitch Stephens in All Saints, Jack Jaffers in The Alice, and Dave Rafter in Packed to the Rafters.
On Instagram, he has 14,6000 followers, but he insists he's just a regular guy.
How regular?
His favourite summer activities are surfing, and eating ice cream - preferably salted caramel or vanilla. "If you can do vanilla well, you're winning."
Favourite movies are Forrest Gump and Jerry Maguire. Favourite superhero is "Viking God" Thor, or Aquaman.
"I was a Thor fan way before Thor became a movie."
He's "easy going, creative and generous." He's most afraid of static shocks.
"I hate when my kids say: 'Daddy, can you get me off the trampoline? I say: Get yourself off."
His pet hate is tailgaters, although he notes Tauranga drivers are pretty good. "South Australians are terrible. And people that don't let you in on the traffic. I don't get angry; I don't get 'rawwar!' (but) it's a peeve."
He's currently listening to Ryan Adams, but by default is pulled back to The Finn Brothers and Don McGlashan. "I always buy their albums no matter what they do, because they've kind of catalogued my life."
His life has seen him play fictional characters not too dissimilar from himself.
He became a household name as father-of-four Dave Rafter in the popular series Packed to the Rafters.
When the series finished after 122 Episodes , he saw 800 Words as a good segway. "As opposed to going from Dave Rafter to a serial killer. I needed a role that was different to Dave, but not too different."
Packed to the Rafters finished because the older kids had left home and it was no longer "packed".
He went underground for two years to give his audience time to care about him again.
"Australia's favourite dad" is a tag sold to the Aussie audience for 800 Words, in which he plays a newspaper columnist and widowed father of two.
Thomson is "mining that seam" but says the next show he does, probably won't be as a dad.
He's okay with being Australia's favourite father though?
"It's a tag that's unfortunately stuck. It's a spurious claim, I think. When I watch the show, I don't see (George Turner) running around being a great father. In fact, I think George is a bit of a useless dad. He tries his best, but makes a lot of mistakes."
What sort of father is he in real life?
"I think I'm a pretty good kind of attentive father. Yeah, I think they like me. Ha, ha."
For six months a year, Thomson who lives a quiet life on South Australia's Fleurieu Peninsula with former actress, wife and artist, Caitlin McDougall and children, Eilish, 10, and Magnus, 6, relocates to Auckland's West Coast.
Last year, his family joined him (Magnus started his first year of school at Remuera Primary) but this year they have stayed behind, and Eilish and Magnus attend a Steiner school.
"It puts a lot of pressure on. I don't want to be upheaving them all the time and putting them into new schools, so we might just try and get a blend of the two (if there's a fourth season)."
While working in New Zealand, he flies to Tauranga from Auckland three to four times a year, but he wouldn't move back.
"There's no work here, but I mean, I like Tauranga. It was a really, really great place to grow up."
Growing up, he was good friends with Tim Balme, who likewise works in TV and was a writer on 800 Words. The pair were in the band, The Gonads, in the seventh form: Thomson at Tauranga Boys' and Balme at Otumoetai College.
"We kind of pulled (Balme) into the band and played for the summer of 84/85. Our first gig was at Oropi Hall."
Were they any good?
"Um, nah, probably not. We played two sets of nine songs but they were the same nine songs twice."
They played everything from The Clash: Should I stay or Should I go, to Boomtown Rats: I don't like Mondays.
"It was a bit of flying nun music from Dunedin and kind of alternative punky early 80s stuff."
Like Balme, Thomson hasn't needed to go far from home to experience success as an actor. To go to LA now at age 50, would be to start all over again.
Of the myriad of characters he's played, he's liked them all for different reasons, but his favourite, was faded rock star Jack Jaffers in The Alice (which co-starred his wife, McDougall).
If a movie was made of his life, what genre would it be and who would play him?
"It would be a musical comedy starring Ryan Gosling."
Why?
"I don't know! He's just the first one that came into my head. He's a singer and and dancer, and I worked with him years ago on Young Hercules (Thomson played Hades). He came out as a 15-year-old and worked out here for about a year. Quite a lot us in Auckland worked with him, so he's our claim to fame. He was a precocious teenager and I kind of thought: 'This guy is an idiot, he'll never go anywhere - Bang! That was major lesson. Never judge a book," he laughs.
What compliment do people give Thomson the most?
"It's a kind of backhanded compliment. They say: 'You're a lot better looking off TV'.
Sometimes they say that just before I'd go onset, and I'm thinking: 'Well, hang on, I'm about to get in front of a camera'. Apparently, it's better if I don't?!"
Growing up in Tauranga, he went to Tauranga South School (now Gate Pa) before Tauranga Intermediate and Boys' College.
His dad, who passed away four years ago at 76, was Dr James Thomson, an obstetrician and gynecologist at Tauranga Hospital.
His mum, Barbara, 77, lives in Bethlehem and Thomson has two sisters - Ingrid, who works for Waipuna Hospice in Tauranga, and Helga who lives in Remuera.
Does his mum enjoy 800 Words?
"I think so, yeah. She's just happy as long as my hair is neat and my clothes are well pressed… She's very proud… and I think because people like it, she gets a bit of feedback around the community."
Part two of series three of the New Zealand/Australian co-production of 800 Words starts in 2018, and Thomson, who also serves as associate producer, says the show has really "gone up to the next level in New Zealand with 400,000 viewers".
"The numbers are kind of unheard of for New Zealand dramas these days.
"It's got a nice blend of New Zealand cultural references, the humour is good, and there's a little bit of that transtasman digging."
It's fair to say he has a good smattering of fans but is cautious when interacting with them.
"Sometimes someone will personal message you, and you go: 'Do I answer that?' It can be an innocuous question, but then before you know it, suddenly you're a mate."
He has a Facebook page but only friends of friends can request him; and he controls his own public Instagram page.
"So you can let out as much as you want… I'm not on Twitter for that reason. I don't want to open myself up to criticism because our egos are all pretty fragile."
Any crazy fan stories?
"I got a letter from a woman who was basically saying: 'If you don't respond to me, I'll kill myself.' That was years ago (when on All Saints).
"She was a psychiatric patient who had just got out of hospital. I just referred her letter to our publicist and she got in touch with some mental health people, because we had her address. I didn't want to just disregard it because I felt responsible in some way she was going to be alright."
Thomson tries to live an ordinary life. His daughter tells her school mates: "Nah, he's not famous, he's just my dad."
As we end the interview, Thomson says he needs to go hunting for a toy shop.
Son, Magnus, was going to accompany him to New Zealand but the trip was then shortened, and he broke the news to him with bribery.
He now needs to find some Lego, pronto.
This famous TV dad, really is just a regular guy.
Erik Thomson is next on TV on The DNA Detectives, where he uncovers Viking links to his family history. TVNZ 1, Tuesday.
