If you're going to excel at something, the younger you start the better. Look at Formula 1 Champions. Schumacher, Vettel, and Hamilton all started in karting when they were little kids, barely tall enough to turn the pedals of a bicycle. Look at Olympic Gymnasts. Nadia Comaneci was 14 years old back in 1976 when she won a Gold Medal, and scored the first, "perfect 10" in the sport.
All of these kids took chances doing what they did, and any of them could have been seriously hurt or killed doing it. The younger you are, the less skill you have developed. And the greater chance there is for a serious mishap. It's no different than succeeding finically. Risk determines reward. The greater the risk over the longest period of time, the greater the reward is down the road. But at any time the whole thing can go against you. Just as it did for this girl. Skill accounts for a great deal. But in a sport like auto racing, luck plays a huge part. And usually if you are unlucky you can get real dead, real fast. Back to Formula 1. Gilles Villeneuve and Ayrton Senna were both highly skilled World Driving Champions. Both had their luck run out. Both are dead because of it.