"I used to do a lot of shearing in North Canterbury in my day and I was shearing all round Canterbury and Otago."
Competing in blade shearing, he won the golden blades at the Canterbury A&P Show in 1975 and 1976 and was world blade shearing champion in 1980 at Masterton.
In 1976, he broke the world blade shearing record, shearing 353 sheep in a nine-hour day at Rangiatea Station, near Mt Somers.
Two years earlier Casserly entered the Guinness World Records after opening 100 oysters in three minutes and three seconds in Christchurch.
Moving to Omarama, he became the local publican for 13 years from 1992 and ran the Omarama Shears for several years, where he won the New Zealand merino shearing title.
Over the years, Casserly has been invited to shear celebrity sheep including Shrek, Big Ben and Suzy.
Coming out of retirement, Casserly placed third in the open blade shearing competition at this year's Golden Shears.
"Gizzy Shrek" escaped from Wairakaia Station, near Gisborne, around five years ago and was found roaming in a neighbouring forestry block.
"They had seen it on several occasions, but it was too wily," Casserly said.
"It had a long tail and no ear tag, but it was quite calm when I got to it."
While "Gizzy Shrek's" fleece was not as heavy as some of the well-known sheep Casserly has shorn over the years, the fleece length off the shoulder was measured at 58cm — 3cm longer than the previous world record set in Masterton in 2018.
It took 15 minutes to give "Gizzy Shrek" the haircut, with the fleece weighing in at 14.5kg, much lighter than Shrek's 27kg trim in 2004 and Big Ben's 28.9kg haircut in 2014.
Now retired on to a 4ha lifestyle block on the bank of Cam River, Tuahiwi, Casserly has plenty of time for fishing for whitebait and trout.
"I'm living the dream," he said.
As for his parting words, now that he has hung up his blades?
"Success is not final. Failure is not final. It is the courage to carry on. You have to want it enough, just stay calm and carry on when the going gets tough. Keep going. You don't give in."