Deadlines (self-imposed, even) make a huge difference for me. Being the lazy, unmotivated, dissolute individual that I am, I can confidently say that some of the most productive, sustained learning efforts I undertook these past few years were Coursera classes with weekly problem set (e.g. coding) deadlines.

Take this with the caveat that advice is what worked for the advisor, not necessarily the advisee. But if you really have this problem of focus, I ask you to consider doing this: go to Coursera, choose an upcoming course that fits your "highly technical subjects" the closest and looks the most appealing in terms of subject matter, and make the commitment to see that course through. If/when you complete it, in the future when you need to focus again you'll at least have that experience to encourage you, reminding you that in fact you can see something complex through to completion.