If you learned that double-Olympic and World Champion swimmer Rebecca Adlington, 22, had two older sisters who liked to swim, you might think you'd cracked at least part of the reason why she became the competitor she did.
But for the Adlington sisters growing up in Macclesfield, Nottinghamshire, the friendly competition didn't stop at the local pool.
In fact, Adlington remembers, they would all race to touch the car first on the way to the pool. And then they'd compete when they got there. And then they'd compete on the way back.
"I didn't win for ages," Adlington tells me about this and other games she played as a child - not surprising perhaps considering her sisters were two and four years older than she was.
And even when her first swimming races began at age nine, racing at the Sherwood Colliery pool, she rarely won those races either. "I wasn't very good when I was little! I did breaststroke too, which is now my worst stroke."
In other sports too, Adlington remembers the sting of defeat. "We didn't have school swimming," she recalls. "But we had every other sport, and I was crap. I was absolutely rubbish at any other sport. I used to dread doing PE lessons as I would never be as good as the other girls. But then as soon as I got in a pool I was off, and I was fine."
Fine is an understatement. It was not all that long from winning her first local club champs - "we got a little commemorative medal, and I didn't take it off for about a week!" - to the 2008 Olympic games in Beijing, where Adlington won a gold medal in the freestyle 400 metres, and then another one a few days later in the 800 metres when she also broke the world record.
Which isn't bad for someone who was still only 19-years-old.
An overnight sensation Adlington went to to receive an OBE and have her local swimming club renamed in her honour. Her most recent success came in the 2011 World Aquatics Championships in which Adlington won gold for the 800m, and now she is looking ahead to the qualification races for the London Olympics, which take place in March next year.
Once she finally won a race, Adlington says, the feeling of victory was intoxicating.
"You can't describe it. So many people after the Beijing Olympics said to me, or asked me to describe, winning, and you can't. It's so personal," she said. "You get so many mixed emotions. It's satisfaction, it's relief. You get joy, you get happiness, you get pride, it's so much that it's just an amazing moment and you never want it to end."
Is it possible to get that feeling any other way? "I've never felt it apart from when I win a swimming race. Ever," Adlington says, disappointingly, as it turns out, for this interviewer, who hasn't won a race in anything for over a decade. "You want to experience it again. It's very addictive."
"I definitely think that's why a lot of athletes make a comeback, because they miss that feeling and I think that's something that I'm definitely going to struggle with when I retire."
According to Dr Jack Lewis, a doctor, presenter and brain expert, the brain "adapts" to winning.
"When you win you get more receptors in the brain that respond to the hormones that help you to win," Lewis enthuses. "You get a bigger rise out of it but also its more efficacious when it comes to improving metabolism and you're trying to get the maximum out of your body."
So is winning down to nature or nurture? Predictably Lewis says it's both.
"For instance," Lewis says. "There is a little test you can do with your fingers that can tell you whether you have a natural propensity to be a good athlete. If your ring finger is longer than your forefinger it suggests that you had a lot of testosterone when you were in the womb.
"This is the same for men and women. People who are successful, whether that's in athletics or in business, or world leaders, there is a very high propensity of people who have this physical characteristic."
But once the basic building blocks are in place, it again comes down to your family environment, your schooling, your desire to win - and those vital games races to touch the car that instill the love of competing.
"The fact that Rebecca had older sisters who naturally would have been stronger in the pool means that she's comparing herself against an impossible competitor," Lewis says. "As a kid who is five years younger than another one is never going to beat them. But I think to be competitive it's good to set your sights impossibly high, and then to reward yourself according to the amount of effort you've put in."
After nature and nurture have done their work, it comes down to the really hard stuff - i.e. training, racing and not losing your mind while trying to do both.
For help with that Lewis suggest taking small breaks while concentrating on a task, like the 'Minute To Win It' games at Cadbury's Spots Vs. Stripes website, to help gain a fresh perspective. Cadbury's, who are one of the sponsors for London 2012, have launched the campaign to inspire the 'champion' element in all of us, and to get the general population playing games on a more regular basis.
Once again, however, it seems like those traits come naturally to Adlington, who always appears cool and collected before a race, even if she doesn't feel that way inside.
"Your mind does strange things. At the world championships this year I realised I was actually quite short compared to the other girls," she jokes. "We were stood in a line and I realised I felt quite small. I thought 'maybe you have to be tall to be a good swimmer'… Your body goes a bit crazy. You notice the adrenaline from the nerves. That's a massive thing for me. You go from feeling sick, to feeling like you want to cry, to wanting to pass out."
It's good to have examples to learn from, Adlington says citing cyclist Chris Hoy.
"He has the best attitude I've ever seen in any athlete in the world. You just can't help but respect him." But with the qualifiers for the London Olympics still nine months away, how does Adlington, or any champion, keep their mind on the task?
"Well I've been doing it since I was 13," Adlington says. "It's no different. Except it's for something that is 10 times greater. You've just got to not let it panic or stress you out. You've just got to do the work."