Many thousands of words have been written about the retired plumber's winning ways in his running career, but who knew that he's been placed second in the humorous section of a nationwide Toastmasters competition? His subject: a parody on his childhood fear of the "murder house" (school dental clinic).
Tickling funny bones is his modus operandi - and his wife Pat's equally good for a laugh.
Their combined sense of the ridiculous will be an invaluable asset as Colin huffs his way around the lake for the 50th time.
A dickey knee's forced him to walk the lake's 42.195km circumference for the past decade. Pat's been walking it for years and training others to conquer what, to Colin, is "the best course in the world".
Who dares argue with the assessment of a man who's "been there done that" 49 times and cracked a slew of international courses?
He'd have chalked up his 50th Rotorua event when the marathon celebrated its golden jubilee last year, but the flooding that wiped out the 1999 event scuppered that.
"I was okay about it then, I had a niggling leg injury, but it's a bummer now because my health's deteriorated, I've got pulse and lung problems; hills used to be my forte - now I see a hill and stop.
"Getting only 60 per cent of the oxygen required into my blood's not conducive to running, [rower] Rob Wardell's got the same problem, so did [the late marathoner] Jack Foster, it's an occupational hazard for hardcore athletes."
Running wasn't Colin's first sport of choice - that was rugby, but when he came off second best in a Waikite club 3rd grade scrum a mate told him he wasn't built for rugby, and to try running.
He was already well trained: "I'd been working on a Hicks Bay sheep station where the only way to catch a goat was run uphill after it, it gave me a lot of my stamina. Hell, those billy goats sure stunk."
We take Colin back to the years that went before and learn he's an identical twin, something he and brother Ian, who died three years ago, milked to the max.
"Once when he went away I took over his girlfriends, they never knew, obviously there wasn't much taste there."
Colin's father was killed when he was 4: "A Road Services bus on the wrong side of Lake Rd took him out, my mother was a widow at 21 with four kids under 5, there wasn't any Winz to go to in those days."
Instead, she went housekeeping and married her employer: "a brute of a man - beat us, beat our mother".
Adopting her children, he insisted they take his name.
"As soon as I started plumbing and had enough money I changed mine back, my brother didn't, it caused the army a hell of a lot of confusion when we did our CMT [Compulsory Military Training]."
Colin "bailed out" of Mamaku School at 15: "I couldn't get a job in the mill because I was too small. My brother was also small but they turned a blind eye; he worked there two days a week, went to school for three ... . we were a couple of cowboys who went to sheep stations."
The promise of Colin becoming a shepherd was never honoured.
"The boss found out I was a champ at chopping wood so kept me at it. If you come from Mamaku of course you're a natural chopper."
Accepting that his shepherding career was pole-axed, Colin came home; plumber John McHale offered him work.
"I couldn't become an apprentice because I hadn't been to high school."
Eleven years on, Colin opened his own business, retiring three years ago: "We've got a hell of a lot more important things to do than work."
Pat's his second wife. Unsurprisingly they met "out running one day"; they were together for 17 years before they married, have been a duo for 30.
"Pat's always believed in trying before buying."
Pat slides into the conversation to reveal his proposal came on bended knee at Sydney's Shelly Beach following a City to Surf run.
They married at the Green Lake picnic area "because we've done a lot of running around there. Whenever I go past now I demand a minute's silence". Attribute that quote to Colin the comic.
They had a sentimental attachment to Sydney, living there for a couple of years in the 1980s.
"I had this mate who bought the worst houses in the best streets, ripped them to bits then sold them, he made a hell of a lot of money, I didn't."
Colin and Pat joined the Sydney Striders: "They had 25 different running places around Sydney, it was a two- to three-hour drive to get to some to start at 6am. We soon learned to run the ones closest to home."
Each year he returned for the Rotorua marathon. His fastest recorded time is 2:35:46 in 1996, his slowest was last year's 7:39:40.
Colin is realistic that today's attempt's likely to take longer.
"I want that T-shirt with 50 on it real bad, even if they have to carry me over the finish line."
COLIN SMYTH
Born: Matamata, 1939.
Education: Rotorua and Ngongotaha Primaries, Mamaku School.
Family: Wife Pat, two daughters, son, two stepdaughters, nine grandchildren between them.
Interests: Family, running, motor home, Waihi Beach bach, Country and Western records, "I've got a couple of motorbikes to do up when I stop running", former member Pioneer Toastmasters
On running career: "I only did it because I like running."
Personal philosophy: "If it's to be it's up to me."
