He is taken back to that day in 2008: Kai's curly hair, his backpack and his timidity. His father was proud and scared.
The memories come easily to Anderson because so many are etched into his right arm — he has eight tattoos of his son's drawings and more are coming.
"It's another deep connection you can have with your kid," Anderson said of his bond with Kai, now 11.
The 42-year-old dad got the idea from his brother, who had a piece of his daughter's art tattooed on his leg. Anderson thought it was another way he could show his love for his boy.
He gets a tattoo once a year when his son comes from Colorado, where he lives with his mother, to stay with him in Peterborough, Ont., for the summer.
The first was a green-and-blue daisy on his inside arm. Then they dug through the scrapbook to search for one he did as a four year old. It was a self-portrait of the boy — a red stick man with a smiley face.
Then it was a house with a laneway and some scraggly lines hanging off.
"I found out later it was actually a mailbox," he said with a laugh.
Then it was a seahorse that was followed by a red maple leaf with the letter 'C.' Some Kai drew in crayon, others in marker.
At the age of eight, Kai's work became more sophisticated with an "abstract stained glass" piece.
Anderson remembers Kai drawing that in his bedroom.
"It brings other memories of the little things they do as a kid, crawling up into bed with you in the morning when they're really little," he said.
Kai skipped the year he turned nine because he wasn't satisfied with his moon-and-stars piece. Then, one of Kai's favourites came last year: a robot butler.
Anderson wants to instill in his son that "you can do lots of different things...draw what you want to draw and be who you want to be."
For his son, it's just fun.
"It's just a different way of expressing art, and it's our unique way of doing it," Kai wrote in an email.
The pair has already picked out this summer's piece: a broken sword that Kai gave to Anderson in his Christmas card this year.
Kai will help Anderson's tattoo artist, Tedd Hucks, when they put ink to skin. The boy has helped with the needle on small parts of the past three tattoos. Kai loves that part, Anderson said.
His dad remembers what his son told his teacher he did over the summer break one year:
"I tattooed my dad!" Kai screamed.
Note to readers: This is a corrected story. An earlier version had the incorrect state where Anderson's son lives with his mother.