If you are looking for profound theoretical insights in Deep Learning, you will be disappointed, but amazed with classical ML. If you are looking for practical

If you are looking for profound theoretical insights in Deep Learning, you will be disappointed, but amazed with classical ML. If you are looking for practical capabilities, you'd be amazed by Deep Learning but frustrated with classical ML. Deep Learning is fairly trivial math-wise (unless you look carefully into non-linear optimization it uses, which is as brutal as any other advanced part of math).