ANDREJ KARPATHY COULD HAVE CHARGED $2,000 FOR THIS. he put it on YouTube for free. 3 hours. the full picture of how LLMs actually work from the ground up. not "here's how to write better prompts." not "here's my AI workflow." tokenization. neural network internals. why hallucinations happen. tool use. reinforcement learning. RLHF. DeepSeek. AlphaGo. the engineers who understand this build things the ones who only use the tools cannot even imagine. most people will scroll past this. watch the 3 hours. the gap between you and the people who did is not 3 hours. it is every single thing those 3 hours quietly unlock for the rest of your career. follow @cyrilXBT if you want to know which resources actually matter.