[Chris2048]

A few issues:

1) applications rest on the shoulders of giants, it isn't efficient to learn too much more than you need to. If you only need to "understand" at a high level, you should just use tools that "do it for you" at lower levels - It's just a shame there are not better FLOSS competitors to Mathematica.

2) It should be clear what the "understanding dependencies" are - i.e. when some knowledge of the foundations can inform the higher levels, and when they don't. If I understand what 'sorted' means, I don't need to know the details of any specific sorting implementation to use it.

3) The way mathematics is split up into a million small, set-theoretically-abstract lemmas etc makes it so much harder to understand. It makes even familiar concepts hard.