Saw this earlier today on Reddit as well - this is truly a goldmine of useful information. The range of topics he covers is simply amazing, with everything from basic chemistry to fractional reserve banking. This man even quit his job as a hedge fund manager to pursue this non-profit full time, so it's definitely a worthwhile cause to donate to if you're capable.

Personally I'm going to try to watch a video or two every day, even for material I already know. His videos are short and they do a great job of refreshing old knowledge.