His mother, Shirley, died shortly after his parent’s 55th wedding anniversary late last year.
"She didn’t know us at the end," he said of the cruel blow dementia struck to the close-knit family.
"It’s not a nice thing."
But if there is one thing Dassen has learnt from his mother’s death it is that as one door closes, another opens.
Earlier this year Dassen (50), who had never actively taken part in sport of any kind, stumbled across the 12-week RU Fit campaign organised by former Highlander Buxton Popoali’i in conjunction with the Highlanders franchise and the University of Otago.
"They had us doing things that I never thought possible," Dassen said of his introduction to a fitness regime.
That spurred Dassen on to jogging short distances.
Then his boss at PlaceMakers, Justin Macready, challenged him to enter the Cadbury Dunedin Marathon with him.
Dassen took up the challenge with encouragement from his children, son Michael (22) and daughter Natalie (19), both of whom have excelled in various sports, and wife Brenda.
Noticing how easy his jogging was becoming as he kept at it, Dassen ran the quarter marathon distance in training a couple of weeks ago.
"I felt a bit like Forrest Gump. But hey, I did it."
In the past week, Dassen twice jogged 4km.
"I was determined to finish and really wanted to be there at the end," he said of completing his run yesterday and being greeted at the finish by his wife, daughter and father, Nick.
"That was awesome crossing the finish line. The emotion and adrenaline rush was like nothing I’ve ever experienced before.
"It is quite an achievement for me. You never know where it will lead. I had always felt unco-ordinated when it came to sport. But hey, here’s something that I can do and I’m making a change to my life. Prior to this the closest I came to running was getting from the car to the house in the rain."
Another incentive was the donation Dassen said his boss promised to make in aid of prostate cancer, for which PlaceMakers is a major sponsor of Blue September, if he finished.
