Sylar is an exceptional, gifted young man that recently graduated from an accelerated program at MIT. His parents adopted him late in life after his biological parents died in a car accident. As the only child of Vito and Martha Patrelli he was doted on in his childhood. While not spoiled, he did come from an environment that ensured his needs were well cared for, including the costs of his education with intensive tutoring in addition to private schooling.
While this did leave him somewhat sheltered, he isn't naive by nature.
Due to his age, and the mix of degrees he graduated with, he was approached in what was effectively his junior year for recruitment into the agency. He spent his senior year in the agency training program while finishing his university courses.