Sarah Walker's horror crash in California two years ago may have been unforgettable to those who witnessed it, but not to her.
The 27-year-old Walker can't remember a thing about the day which came perilously close to ending her career, or something far worse.
Walker has zoomed back into the right sort of headlines after a brilliant win in the Oceania Championships last month but then just as quickly found herself creating the wrong sort with a crash on Wednesday that broke her arm and places extra pressure on her bid to ride at this year's Olympics.
Her return to the forefront of Olympic news seemed a perfect time to reflect on the unique career of a young woman who has essentially put a new sport on the map in this country and proudly sees herself as a trailblazer for her gender.
She is in household name territory, for riding a bike that until not too many years ago was something most people thought belonged under a Christmas tree.
The London 2012 Olympic silver medallist has been in the vanguard of getting BMX recognised as a legitimate sport.
And nothing illustrates why little bikes should be big news more than what Walker endured to keep alive her dream of going to the Rio Olympics.
Her body has been broken again and again, the cracked bone count having hit 15. The severe concussion she received in the 2014 World Supercross event would make even the toughest footballer cringe. Walker had a camera inside her helmet which at least gives her an idea of what happened.
"My helmet didn't have a lot of scratches so I didn't hit the head that hard - it was just the angle," she says at the track in Cambridge, the newish home town of cycling and her home for the past six years.
"I have no recollection of that entire day, although I've watched the GoPro footage three or four times. It filmed for eight minutes afterwards and the weird thing is that it didn't look like I got knocked out at all. I was completely conscious. It is weird, but every head injury is different.
"The first seven or so minutes, I seemed completely aware of everything and was going over exactly what happened with the medical staff, letting them know that I hit my head hard but could remember everything. Then I got to this point where I'm having deja vu. I started repeating myself every few minutes for the next seven hours."
What came next is just as frightening. The six broken bones in her arms hardly rate a mention beside the concerns about her brain injury. She had a headache every day for six weeks.
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Three months after the crash, the interior design student tried to do an hour of study, and had to give up and sleep instead. The headaches returned for two days. It was five months after the crash before she got a medical clearance.
"It was a massive head injury and I don't remember most of the recovery part," she tells the Herald in an extensive interview after a training session before her latest mishap.
"I was lying in bed, pillows supporting my arms, but I had no hating for BMX. I was missing it, the joy of flying through the air. I had an amazing feeling from the very first time I rode a bike - I loved it instantly.
"I was lying there all broken and all I wanted was that feeling again. It never crossed my mind that I would stop. The thought that I might not be able to, or allowed to because of the head injury, was the scariest thought."
Walker wanted to be an Olympian from the day she watched freestyle swimmer Danyon Loader atop the podium, anthem playing, at the 1996 Atlanta Games.
Walker found BMX in what was a traditional way for a girl back then - via her brother's involvement. Matt was two years younger. A sibling rivalry, a driving force, was born and anything Matt could do, Sarah tried to do better.
"A 10-year-old girl doing jumps ... it turned out that no one else was doing that," she says.
Whakatane and Kawerau-raised, she was into anything and everything sports-wise, at a time when BMX was barely a twinkle in the eye of the Olympic Games. A track cycle loomed as the likely vehicle for her Olympic dream, and she was six months shy of quitting BMX when it was announced as a sport for the 2008 Beijing Games.
But to most people, BMX was still something that belonged to the boy next door. When the subject was raised, she was invariably asked if she could do a back-flip, to the point that she tried to learn the art in order to have a positive reply at the ready.
A fourth placing in Beijing got her noticed, a silver medal in London got her and the sport much more than that.
"In the beginning, sponsorship was really hard, fundraising was really hard," she says. "Even after Beijing, it was the same, although it made a huge difference to people's understanding of the sport. The beef and lamb adverts I was in also helped."
Public perception be dammed. A BMX race is 40 seconds of terror, starting from a six metre high ramp which, come Olympic and world championships time, rises to eight metres.
Walker and friends will reach a speed around 60km/h in a tick over two seconds when they plunge off the Rio ramp - "the acceleration of a supercar like a Ferrari" she proudly points out.
Massive speed bumps and short flat patches in between await, on a curling course which is attacked with fury by eight riders per race.
Walker admits to scaring herself, and wondering how she does it. Even training can shatter the nerves.
"Last year, at every World Cup, we raced in horrible conditions - lots of wind and a couple with pouring rain," she says.
"I love it when it's perfect at training but I hope it's not perfect most of the time. It's a love-hate relationship.
"When it is windy, it pushes me to be even better, even though it's more scary because the chances of crashing are much higher."
When the Herald caught up with Walker last month, she had just escaped another frightener.
"If I was to look at BMX without my helmet and off my bike, I'd see it like other people do ... some of the jumps are humongous and even I would question how can I do this," she says. "But when I put my helmet on and ride towards it, it's a different perception and I know I can do it. We try really hard to make it look easy but there are definitely times when fear is through the roof.
"Even today, for example, I almost had a crash and managed to stay on but it scared me a lot."
Fear, pain, broken bones, the dreadful concussion and a handful of other "minor" head knocks ... BMX is like gladiators on bikes in a mini colosseum. And the toll on Walker has been greater than most.
But after four years of injury setbacks, Walker performed brilliantly to win the Oceania title at Pukekohe and kick start a belated Olympic qualification process that would have been done and dusted but for the California crash.
She is back, it appears, better than ever - not withstanding her latest injury setback. And she needs to be, because standards are constantly rising, and the world's tracks - to her disappointment, she makes clear - are getting more acrobatic and less about pure racing.
She defeated world No4 and London Olympic finalist Caroline Buchanan and her Aussie compatriot Lauren Reynolds under intense last-race pressure in the Oceania event, and says it was also a victory over the constant fear of getting injured again.
Qualification races in Argentina, England, Holland and the world champs in Colombia - the home of Olympic champion Mariana Pajon - await. In a weak field of five remaining Olympic hopefuls, Walker is super confident of closing the deal, probably alongside Thailand and Belgium.
As a measure of what is needed beyond that, she is already ahead of where she was on the eve of winning silver in London (before Wednesday's crash), although she says performance and not medals are her motivation.
Walker, it seems, is still pulling the sport along and the sport is pulling Walker along. As an Olympic event, BMX is still in its infancy but has made giant strides already. As has Walker.
She is adamant that if she had used a sports psychologist leading up to Beijing, she would have won a medal. With David Galbraith on board, she was able to get in the right frame of mind in the nick of time in London.
The night before the final, she was "freaking out" because eight years of preparation had reached an "overwhelming holy-moly" point.
The thought of winning or losing felt daunting. She felt afraid, strong, fast all in one.
She sent Galbraith a long email. The morning brought his equally long reply, which included a match video involving tennis aces Novak Djokovic and Roger Federer. The Serbian had saved a match point, had a couple still to go, but was smiling, taking in the crowd's reaction, soaking up the moment and pleasure of a huge point won. And he went on to win.
It switched Walker into the right mood, of embracing the pressure and occasion, taking control of her destiny by refusing to back off or play the race safe.
Four years on, she is not driven by the need to win gold, but instead revels in having placed no caps on her potential, of being able to give every step of the way everything she has.
And she comes across as a woman who is very comfortable in her own skin - charming, engaging, accommodating - rather than someone haunted by unfinished business. Life has been good.
"I didn't even dream this crazy dream," she says. "I did every sport imaginable as a kid, figuring out what I would be good enough to go to the Olympics in. BMX was the sport I loved on the side but back then, it wasn't the sport that was going to get me there.
"My life has been so insane and amazing. So when I tell kids to dream, I say dream even bigger and reach for the stars.
"The most important thing to me is that I enjoy riding my bike and give it 100 per cent. The knock-on effect is it inspires others to do the same.
"It is great that it is recognised as a legitimate sport in New Zealand now and the next generation of kids coming through will get a lot more support.
"But the coolest thing I've experienced isn't so much the rise of BMX racing - it's more about girls doing the sport," she says.
"When I started, all the girls I raced did so because they had a brother or a cousin who raced.
"Now, girls tell me they have got into it because they can see that girls can do anything. I find that really cool."