Clyde Rathbone suffers a concussion for the Wallabies in 2004. Photo: Getty Images
Tiny grey spots appeared, as though television static had invaded my field of vision.
Then a distant voice began posing confusing questions. How old are you? What day of the week is it? Who are we playing?
Suddenly, the blurriness vanished and I was shot back to reality. My vision cleared and I found myself shouting back ''I'm fine!'' It was July 3, 2004, I was in my rookie season as a Wallabies representative, playing against a combined Pacific Islands team in Adelaide.
I'd just received a concussion, but I recovered quickly enough to convince the doctor I was fit to continue playing.
I received a second head injury later in the game and couldn't sleep that night due to a persistent pounding headache.
By the Monday, I had no symptoms - that is, I knew who I was, I had a decent grasp of the calendar and my headaches were gone.
It was enough to clear me to play the next weekend, in my first Bledisloe Cup, a Test win against the All Blacks in Sydney.
Times have changed and brain injury in sport is a hot topic.
Concussion has become a dirty word among sports teams, often substituted for the now popular euphemism ''head knock''. Despite this, retirements from brain trauma are rare in rugby - although they do occur.
I remember Elton Flatley's final Test match for Australia.
Flats was the kind of tough teammate I loved playing with because there was never any doubt he would put his body on the line.
Repeated concussions had left him struggling with blurred vision during matches, though he seemed to have overcome the problem leading into our Test Match against South Africa in Perth in July 2005.
During the warm-up, Flats got nudged by one of the reserves holding a tackle pad. It was a totally innocuous collision, but it was enough to effectively end his rugby career.
South Africa's Krynauw Otto retired at the age of 28 after medical examinations revealed a subdural haematoma in the left frontal area of his brain. After complaining of headaches during training, Otto required surgery to drain blood and relieve pressure on his brain.
This week, the NRL released its rigorous new concussion laws, along with stringent sanctions for clubs who fail to abide by them. Teams now face the potential loss of competition points or large fines for putting a player back on the field with symptoms of concussion.
NRL head of football Todd Greenberg said: ''Rugby league is a very tough sport but player health and welfare is at the forefront of every decision we make. Clubs need to understand these are very serious issues.''
Rugby union has recently undertaken similar steps. Players are now required to complete two separate baseline tests, which are then used to assess a player's recovery from concussion.
In addition to these tests, the pitch-side concussion assessment protocols will continue this season.
Encouragingly, the pitch-side assessments have led to a marked increase in players being permanently removed from the field of play following a head impact.
Match-day doctors assessing head injuries will be independent and steps are being taken to make video footage available to doctors to assist accurate diagnosis.
Despite these changes, I can't stop feeling that current players are guinea pigs in a large, poorly understood experiment.
While it's useful that the link between brain injury and contact sports is becoming less blurred, what's being revealed is not comforting.
Increasingly, studies are linking chronic traumatic encephalopathy (CTE), a form of progressive degenerative disease, with contact sports. Some of the symptoms of CTE include memory loss, aggression, confusion and depression. Alarmingly, the onset of the disease can be so gradual as to not appear for decades.
In America, more than 4500 former National Football League players or family members have filed concussion-related suits against the NFL. Last year, the league agreed to pay $US765 million ($855 million) to settle the lawsuit, a figure rejected last month by US District Judge Anita Brody who said the settlement: ''may not be enough to cover injured players.''
When three-quarters of a billion dollars isn't enough to make a problem go away, you know it's worth our attention.
There's an astonishing piece of footage on YouTube from a 1977 bout between 35-year-old Muhammad Ali and his bewildered adversary, 19-year-old Michael Dokes. There were 21 punches, all thrown with vicious intent at a man making no attempt to ''glove up''.
Not a single blow from Dokes lands, the flurry of air-swings ending with Ali taunting his challenger with a wiggle of the hips.
You don't need be a boxing aficionado to appreciate the clip, which demonstrates the incredible evasive skills and sheer hubris of Ali.
Yet despite his artistry, we know Ali was repeatedly and brutally struck in the head over the course of his boxing career.
Three years after his retirement, he was diagnosed with Parkinson's syndrome, a disease often linked to head trauma. Known for a wit as sharp as his punch, Ali's speech is now laboured, and his body, once a floating butterfly, has become leaden.
While concussion protocols are designed to mitigate risks, the future doesn't look bright for brains that insist on hammering themselves for sport.
Rugby players are getting bigger and faster, and collisions are becoming increasingly violent and frequent.
The intensity and physicality of the game cannot be allowed to subside - there's far too much money at stake for that.
Rugby players are modern-day gladiators, and like gladiators we are subject to the primal cravings of the horde.
It's not difficult to envisage a future where our enlightened descendants shudder as they reflect on a barbaric spectacle once called rugby.
It's difficult to know the long-term implications of repeated head traumas resulting from sports such as rugby.
It's this gap in understanding that makes it unlikely I'll be encouraging my future children to play rugby, at least not until further research gives a more reliable picture of the risks involved.
This attitude might be accused of being ''precious''. But what is more precious than a human brain?