My thinking is that to have success, one must have an objective. That is sometimes the hardest part. A person can study this stuff all day, but unless there is a tangible problem to be solved, all is lost.
So one must have a need, such as a sprinker timer, lighting timer, garage door closer if I forget, ......
Otherwise, if no problem to be solved, no gain from pursuing this.
I speak from decades of such experience and success.
I also believe that this thinking applies to everything in life. Sort of like teaching a man to fish vs. giving a man a fish.
One must teach oneself, but the harder part is knowing what to learn. To know that, one must know what problem needs to be solved.
That said, I have a problem that drew me to this possible solution.
I have a GoPro camera.
When I shoot "film" by hand, it is unstable.
At first, I thought I needed a slide.
But when I created a slide, I realized I needed a motorized slide.
Then I realized I needed a precise motorized slide...and one that could move all about (up and down, back and forth, side-to-side) with precision.
And then I discovered Arduino.
I have yet to create the product I need, but I have already envisioned it (i.e. created it in my mind...and am continuing to do so).