IT is heart-wrenching to hear of little Oscar Knox's pain and anguish on his parents' on-line blog. Leona and Stephen have had to watch their precious five-year-old "go through hell" in the last few weeks as a result of the rare and aggressive neurological cancer he was diagnosed with in November 2011.
The couple have had to witness their adorable child screaming in constant agony while morphine, sedatives and anti-anxiety medications are administered 24 hours a day.
In quieter moments, they note, he has whispered to his mum and dad that he doesn't "want to be a boy anymore", and "I don't want to be me".
It makes difficult reading, and it doesn't sound like the sparky little fighter who has captured hearts around the world.
But there are still signs of his admirable spirit in the diary. Oscar hasn't given up his battle and is still surprising his doctors.
Recognising that his awful neuroblastoma disease has progressed radically, the Knoxs and their youngest child Izzie are now watching over Oscar as he battles on in the Children's Hospice, on a high dose of diamorphine that would knock an adult patient for six – but not this courageous child.
With his famous sunny resolve, this cherubic little boy is conscious and functioning – "that is our wee Oscar all over," as his parents write.
They had told his consultant a couple of weeks ago that they didn't think Oscar would succumb to the diamorphine and he agreed: "Your son doesn't do giving up."
After Oscar's first long and tough battle with his childhood cancer, he was given the all-clear in April 2013. Sadly, the disease returned last August.
Since then he had five months of fun-filled relative stability, a light-filled time in which he has been star of the show at the wonderful fundraising events at the Royal and the NI Children's Hospice. He has eclipsed all others with his winning smile and radiant spirit, with his cute little face and happy-go-lucky demeanour.
Even Summer, the miniature therapy horse, has a soft spot for the little boy. As his owner Samantha Hayes remarked: "Summer makes a bee-line for Oscar on his visits to the Royal Victoria Hospital and the Hospice on therapy days and they have an amazing connection.
"Oscar is a ballsy wee lad and that's what has got him as far as he's come."
Unfortunately, neuroblastoma is a cruel disease which goes back on the attack just when its devastating effects seem to have abated.
The year before its ravaging effects surfaced in the then toddler's body, he learned to walk and welcomed his newborn sister home.
Endearing photographs online show him taking some of his first steps at a family wedding, and cuddling the infant Izzie.
In the dozens of pictures which have appeared of Oscar since in the media, he invariably has a big, bright smile on his lovely little face.
It's this beaming grin – and the positive spirit behind it – that has branded itself onto our collective consciousness. And it's one many of us will never forget.