The Class M farm world where Worf was raised by the Rozhenkos after he was orphaned at Khitomer had barely 20,000 human colonists, but enough for its schools to have teams playing sports such as soccer. As the only Klingon he was the biggest and strongest, but the fatal neck injury he unintentionally inflicted on a soccer opponent at age 13 left him cautious and restrained for fear of hurting others. He and his foster brother Nikolai entered Starfleet Academy at the same age, but the human youth disliked it and returned to Gault before striking out on his own.