According to the Maa.org, when Niels H. Abel was asked how he gained his expertise, he replied, “By studying the masters and not their pupils.” I would say tha

According to the Maa.org, when Niels H. Abel was asked how he gained his expertise, he replied, “By studying the masters and not their pupils.” I would say that, especially in cases where the “masters” lived long ago, pedagogy and terminology have often evolved quite a bit and it might not be such a great idea to start with the original sources. Feynman had something to say about that, IIRC. Also, ego aside, it might be easier to understand a presentation from a sympathetic pedagogist closer to your level. Some original thinkers are quite formidable.