I don't disagree that it's important to really understand the code/system/tech that you work with and change, but I personally only reach that understanding in

I don't disagree that it's important to really understand the code/system/tech that you work with and change, but I personally only reach that understanding in the first place through trial and error. My preferred way of learning is always to do a little reading to build a mental model of how something works, and then a lot of experimentation to validate or invalidate that model.