IMO, one should understand that software is the current era engineering focus. Just like electrical engineering in mid-20th century, aeronautical engineering in

IMO, one should understand that software is the current era engineering focus. Just like electrical engineering in mid-20th century, aeronautical engineering in the early 1900s and steam engineering (remember, the origin of the term "engineering" is "engine") for some centuries before that. Before that there were optics and mechanics. Considering that software isn't just a branch, but a current "engineer's engineering", the more complex, flexible, powerful area, a good software engineer should strive to maintain and expand his knowledge in other areas as well. Physics(actually, natural sciences) and math, and also other traditional branches of engineering can provide a lot of useful material. Search there too. "Quantum Computing Since Democritus" is a good specific example, I think.