Note my screen name. I have been doing, learning, and teaching system admin and programming for a very long time. It has always been by Hacking. It does have another description in my mind : Learning by trying things out.
This has nothing to do with malicious actions. It has to do with the tactile feel of doing something to consolidate learning.
I have a hobby of playing with breadboard electronics. Hacking at it has given me much more practical understand than any EE equation. Math is not the Limiting issue. Doing it made it real.
A blogger suggested picking a skill that has nothing to do with your core interests. I learned crocheting in a week by hacking and getting expert advise from my 86 year old Mom. Yes I created 4 of the most ugly swatches imaginable but the last one looked almost acceptable for newbie.
Hacking can be applied to any learning process.