But that doesn't matter if all you want to do is low-speed digital electronics like Arduino and microcontrollers. I think the problem is that you don't know what you don't know.

So, practical basics. Understand the concepts of Voltage and Current. Learn what resistors and capacitors are: find a site that has basic linear circuit theory (Ohm's law, Kirchoff's voltage & current laws). Understanding those two components and wiring is basic to everything else. There's a lot of misinformation out there and knowing the basics will help you avoid being trapped by it. You don't need to know the depths of circuit theory: a good overview will get you on more solid footing than most of the "makers" out there.

Want to learn to build audio circuits, or RF or precision instrumentation? Move on to active circuits: transistors, diodes, op-amps. Read everything you can on proper grounding.

Want to blink LEDs and do more "real-world" interfacing & control stuff: find a site on microcontrollers (the Adafruit learning series for Arduino is pretty good), learn about interrupts, analog to digital conversion, digital to analog conversion, sensors, etc.