I think it works for the same reason _A Modern Method for Guitar_ works.. by not using a familiar context (tunes/languages), you have another vantage point to help internalize the lesson.

I got up early everyday and read a chapter before work and tried many of the exercises. Now I use the whole set as an almost daily reference where I work. The prelim math you can get from MITs 6.042 either on OCW or the reg school site https://courses.csail.mit.edu/6.042/spring16/class-material.... if you just want to understand on an applied level what's going on. I did it in MMIX using the book 'The MMMIX Supplement' by Ruckert to check answers.

Re: SICP I noticed Harvard and other schools typically have an intro to CS course then a course after in abstraction using OCaml or other functional language. The syllabuses I've found for these second semester CS intro courses looks almost identical to SICP ToC except no hand rolled compiler which is probably the single most useful chapter I've ever read in any CS book.