Most children aged 13 months are just finding their way in the world.
Ollie has already had countless operations, gone through chemotherapy and had a 2kg cancerous tumour extracted from his tiny body, but he has bounced back every time.
Now, after months of uncertainty and upheaval, life is slowly returning to normal for Ollie and his family.
His mother, Julie Dovey, said her son had a normal start to life in May last year but that all changed when a routine Plunket three-month check earlier this year revealed he had an unusually bloated stomach.
The Plunket nurse recommended Ollie be seen by a doctor, who immediately referred him to a Dunedin specialist.
Ollie's enlarged stomach, originally thought to be a bowel blockage, was diagnosed as an enlarged kidney with a tumour attached.
The next day - March 16 - the family was on the road to Christchurch for scans and tests.
Four days later, a biopsy revealed the tumour was cancerous.
Looking back, Mrs Dovey said that was probably the hardest moment.
"Your world gets turned upside down once you are told your child has cancer."
Ollie was put on a four-week treatment of low-dosage chemotherapy to try to shrink the tumour.
Although the cancer was killed, the tumour continued growing to a size of about 15cm wide and 13cm high.
On April 23, surgeons removed the 2kg tumour - the size of a full-grown head - and said they were pleased with how the procedure went.
Ollie had won that battle, but not the war, Mrs Dovey said.
What followed was four weeks of post-surgery chemotherapy which finished on June 1.
This was needed to reduce the likelihood of the tumour spreading to Ollie's other kidney.
In his case, there is a 10% chance of that happening.
For now, Ollie is doing well, despite a recent return to Dunedin Hospital with a high temperature - a symptom of his treatment and condition.
Ongoing three-monthly checkups are all he "hopefully" needs for the next few years, Mrs Dovey said.
For her, partner Alton Hay and their daughter, Jarna (8), Ollie's short life so far had been full of ups and downs.
"To be honest, it has been a roller coaster from hell," she said.
But one quick look at her "cheeky monkey" erodes the bad memories.
"We are very, very, very lucky," she said.
