James Cameron never went to film school. He was earning his livelihood as a truck driver, but the true calling of his heart was to make movies. On weekends Cameron went to the nearby university and found papers written by film students, articles on cinematography, books on things like cameras and acoustics. Anything that might possibly pertain to filmmaking. He made photocopies of everything and took those home and put them in binders and studied the hell out of them. He estimated later that he spent $120 on copying, but was getting a full blown education on filmmaking for it. A few years later Cameron decided he knew enough and set out to make his first film. I forget which one it was but sometime soon after he was working on Piranha 2 when he caught the flu. During his fevered delirium he had a vision of a metal endoskeleton with glowing red eyes. He wrote it down. It became the inspiration for The Terminator. He directed that and that led to Aliens and that pretty much solidified his career as a filmmaker.
The guy knows more about hard work and sacrificing for your dream than probably most people.