"Nowadays, when you're not a grandmaster at 14, you can forget about it." (Anand?).More explanation?

The most of modern chess champions are a 'products'. From the age of 3 or 4, they constantly train with a professional trainer 5-6 times a week. Therefore, there is nothing surprising in the fact that when they are 10 they are at least candidate masters (experts) or even masters.