The keen motorcyclist had knocked off after a long day at a Gosnells supermarket, where he had been manager for several years, and was keen to get home to his wife and two kids.
The next thing he remembers is waking up in hospital as an amputee.
His right leg above the knee was removed after he was thrown from his bike when an elderly driver crossed into his lane, but, as Mr Cook said, that is a story for another day.
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READ NOW"When I woke up without a leg I thought my life as I knew it was over," Mr Cook (58) said.
He was given a sleeve and socket, the standard prosthesis given to amputees, but opted out and used a wheelchair and crutches to avoid the fiddly and uncomfortable attachment.
Amputation did not slow him down. He travelled the world in his chair and became a support person for fellow amputees by visiting them post operation in hospital.
"At the time I became an amputee there was not a lot of peer support so I founded Amputees in Action," he said.
Although the organisation is now defunct, Mr Cook continues to support fellow amputees online and through amputee body Limbs For Life.
"It's daunting for people not to feel"normal" but there is life after amputation and there is help if you need it. It is helpful to talk to others," he said.
Last year Mr Cook became one of 200 amputees worldwide to receive an implant-like prosthesis called osseointegration, which cost more than $100,000. It has put him back on two feet for the first time in 15 years.
"Knowing what I know now I would have sold my house to get it sooner," he said.
There are more than 200,000 Australians amputees according to Limbs for Life.
National Amputee Awareness Week ran from October 4-11