Mark Martin was cleaning out the gutters at home in 2012 when he bumped his chest against them and noticed over the months it started to get more sore.
The 54-year-old didn't know men could get breast cancer until an offhand comment to his doctor eventually resulted in his diagnosis.
The National Breast Cancer Foundation has called for men to look out for the symptoms of the disease, with nearly one in 675 Australian men diagnosed in their lifetime.
The foundation says 164 Australian men will get breast cancer in 2019.
"I didn't really know how to decipher it.," Mr Martin said.
"It took me probably six months or maybe even longer, even after I'd been diagnosed and had the surgery, that I could actually believe that (a) man could get this."
Mr Martin said he'd bumped his chest in a spot where he had a boil lanced as a kid.
When he mentioned it to the doctor though, things moved quickly; he was diagnosed 10 days after a biopsy, then had surgery 10 days after that.
He said he took the diagnosis as a challenge to be honest.
"I wanted to talk about it openly because then I'm bigger as a man by actually facing it and dealing with (it)," Mr Martin said.
He estimated about 90 per cent of men don't know they can get breast cancer.
"I mean the whole word 'breast', men don't think they have breasts, men have chests," he said.
The foundation advises men to look out for lumps on their chest which may become more tender.
It said abnormalities around the nipple - like inverted nipples, dry skin, open sores or pimples - could be a sign of a tumour.
Mr Martin said the language around cancer had been confusing, fearing he had a terminal stage for months before a doctor clarified it for him.
"The word 'cancer', it's such a line in the sand," Mr Martin said.
But he's been cancer free since 2012 and says it's been an eye-opener.
"My life is better because of it in many respects, you appreciate life so much more," he said.
Australian Associated Press