East, a project manager, sheepishly admits he had about 12 or 13 concussions over the space of six seasons before his family persuaded him, aged just 22, to give rugby away.
It seems "ridiculous" to him now that Saturday after Saturday he kept taking the field and kept throwing himself around.
But telling your teammates you can't play because you're still feeling a bit foggy after last week's game didn't really wash.
"I guess it's just typical Kiwi mentality, you don't want to look soft so you just get on with it - basically, unless you're in a cast you can play rugby," East says.
"It was pretty stupid when you think about it, but because it wasn't a physical injury - it's not like you turn up to training limping or anything - then you feel silly for sitting out."
If East was one of the nation's rugby stars he could be the poster-boy for the debate over player welfare. Instead he is one of the nameless, faceless casualties of an unreported "epidemic" that festers on club grounds throughout the country.
Living in a constant state of sleep deprivation has taken a visible toll on East. When the Herald visits East at the end of another long day, the dark circles underneath his eyes are pronounced, his eyes bloodshot and bleary.
He suffers from lethargy, can have problems concentrating and his wife Lisa will tell you he isn't the most patient person on the planet.
"It's just something that has to be constantly managed," Lisa says.
"Like if we go out for dinner we will have to pull the pin at about 9.30pm because he just gets too tired. I remember when we were first going out and introducing Stu to my friends, and they all thought he was really grumpy."
"It takes a lot of the fun and energy out of you," East agrees.
More than anything, he worries about what lies in wait for him down the track.
"If this is the effect it is having already and it's only been 10 years, it's like, 's***, what else am I in for?'
"My memory is not as good as it was. I never used to forget anything, but now I tend to have to write everything down."
East's first concussion occurred when he was playing in the under-17 grade for his Collegiate club in Ashburton.
A typically rugged openside flanker, East had just tackled a player and was on the ground when another player came sliding in, knees first.
He still remembers the warm, foggy feeling that came over him - "if you stood in one spot and spun around 20 or 30 times and then tried to walk, that's what it felt like".
From that initial knock, East said it became easier and easier to get concussed, and estimates he suffered a further 12 concussive episodes over the next five seasons.
"It got to the stage that I went and saw my doctor and he basically said that I needed to stop playing now or I was going to do myself some real damage. It was just getting ridiculous, I was getting concussed so easily."
But giving up rugby was anything but easy.
It was a game he grew up on. Most of his childhood memories involve rugby - mucking around in the backyard with his brother trying to emulate the audacious moves of his rugby heroes; the early mornings playing barefoot in the frost, where the promise of a chocolate bar for player of the day was all the motivation he needed to go out there and give it his all; the feeling of pride at being selected for his first age-group team.
He missed - and still does - the physical challenge and the sense of camaraderie.
Still, East thought he had a lucky escape - until his sleep problems took hold.
He first noticed something wasn't right when he moved to Britain, not long after giving up rugby. He was having difficulty getting to sleep, and once he did he constantly woke. East began taking over-the-counter sleep medication, but it had no effect.
As the problem intensified, so too did East's desperation. After trying everything from visiting an osteopath to meditation, he was finally referred to an Auckland sleep clinic about three years ago.
For two nights he was hooked up to various machines and monitors, the tangle of wires measuring brain activity, muscle activity, eye movement and blood oxygen levels.
The readings were staggering.
Not only did the machines confirm East woke up to 17 times a night - something he was acutely aware of after all those nights staring at the ceiling - but they also found that when he was "asleep", he wasn't really sleeping at all.
East was diagnosed with sleep hypopnea: with about 70 episodes of shallow breathing causing a drop in blood oxygen levels. Overseas studies have linked this sleep disorder with concussion. There is evidence brain injuries may produce reduced amounts of melatonin, a hormone that helps regulate sleep.
While the diagnosis gave him some comfort, there is not much that can be done.
He's tried all sorts of strange devices to help him get a more restful sleep - oxygen masks, a tongue clamp and a very novel belt.
"It looked like some terrible S&M device," laughs Lisa.
"It had golf balls attached to the back to stop him from rolling over on his back. He gave up on that one pretty quickly."
Having watched the struggles her husband has been through, Lisa admits she would think twice about letting their children play rugby.
"If we have kids, I'd feel very nervous about letting them play rugby. I mean you don't want to wrap them in cotton wool or take away the fun of playing sport, but given the problems Stu has, it does make you think differently about the game."
A numbers game
* Statistics from the NZRU indicate that about 3000 games of rugby are played every week over an average of 15 weeks
* That's 45,000 games of rugby every year, featuring on average 40 players per game
* An Auckland Rugby source said he believed "literally hundreds of people were playing each week around the city who shouldn't be".
