I wish there were some sort of open-source prerequisite chain of what order to learn any subjects in. That's the hardest part of self-learning. Elon Musk had a reddit AMA recently where he was asked how he knows so much - he responded that he thought everyone had the capability of learning more than they thought, but that the key was to look at knowledge as a semantic tree. If you learn things in the wrong order, they won't have anything to hang off of.
