A Chapter A Day Keeps Stagnation Away
Technology moves fast. Take the new programming language I'm learning as an example. It didn't exist when I first started writing apps. This particular language switch is like the difference between knowing how to drive a car and learning how to pilot a plane. While both are vehicles with controls that take you places, the way you get from A to B is profoundly different.
Blogs and tutorials
This type of re-tooling is optional. Continuing with the old language would work just fine. Learning a new language while maintaining a day-job also means months struggling through the early, painful parts of the learning curve. Things that take an hour with the old take days or weeks with the new.
the programming language I'm teaching myself didn't exist when I started writing computer programs.
I'm teaching myself a new programming language that didn't exist when I first started writing code. The difference between the new language and the one I've been using is substantial. Like the difference between English and Mandarin Chinese.