"They didn't believe it was my work because they said I had done too much work for such a short time."
Dewes said although was given a score of 59 out of 60 he wasn't given a pass for his work.
After leaving high school Dewes honed his skills at Toihoukura School of Māori Visual Arts in Gisborne.
He has held exhibitions locally and internationally, with his current exhibition "Year of the Mask" on now at Gisborne's Tupara Gallery.
All exhibition artwork is related to Covid.
He started the paintings in lockdown in 2020 and finished during the last lockdown in August this year.
His work is heavy with symbolism.
"The chains represent lockdown, lightning symbols represent your thoughts or whakaaro and the exhibition also has a lot of masks in it."
Dewes encourages people to have their own interpretation of his work and likes them to share it with him.
His love of hip hop music is a strong influence.
The symbol of the Wu-Tang Clan, a hip hop group from New York, is evident throughout his pieces. Dewes was even nicknamed Wu Tang at art school.
"It's always been like a kaitiaki (guardian) symbol for me because it's a bird."
Dewes said his real passion is large-scale paintings, his farmhouse home a canvas.
It is 10km up a gravel road and through a stream in Ruatoria.
"I just found it really drab, so painting artwork on it actually brightened it up for me."
His motto is, if you don't like it you can just paint over it and start again.
His next mission is to paint the roof, hoping to have that finished in the next few months.