What bothers me about this article is the hook: if you can learn this stuff you can get a quant job on Wall St. Realistically, very very few people can (truly) learn this amount of material on their own, and even so, you will be competing with top people with advanced math degrees, so if you're not the second coming of Gelfand, the goal of getting this kind of job is completely unrealistic.

On the other hand, if you have the time (and ability) to learn some of this material on your own, for a purpose other than competing for a highly paid job as a mathematician, great.