It could also be that those three people had started practicing earlier than him (AP classes, community college, retaking the course after failing), had tutors

It could also be that those three people had started practicing earlier than him (AP classes, community college, retaking the course after failing), had tutors which provide knowledge at a vastly higher pace, or had related knowledge (highly advanced math, physical chemistry) that gave them an initial advantage. Also, a college class provides nowhere near 10,000 hours of practice. Perhaps things would even out after the first 5,000 hours.