It is generally not neccessary to know how it works all the way down.

It is usually enough to know what it is to a certain degree. Concepts and ideas are far more important than syntax details.

What works well enough for me is to pirate (I know I am a bad person) technical books, put them on my old Palm-pilot and read them while on the train/bus etc. In this way I use time that would otherwise be wasted anyway and I actually find it entertaining.

In this way I get a high-level understanding about things that I can then deepen should the need arise.