I learned a ton about volts and amps playing with legos technic
as a kid. Those 4.5V motors really took a beating from me. I figured out real quick what serial Voltage means. It means the lego explodes and flies all over the room when you put 18V into a 4.5 V motor.
I learned all about amperage when playing with car stereos in my teens. Lots of smoke got released into the environment from loose wires back then.
I learned a great deal about cable lengths and voltage drop messing with rockets. You can only get so far away before there just isn't any juice to ignite the rocket motor. I learned all this also with HO scale trains, you just can't have 400 yards of track and one 12v input, it just won't work! In the Army, I really learned a lot about voltage drop from the helicopter I drove.
If that starter battery only has 24V, that 24V starter in the back isn't going to work, as long as it had 28 or more, we were flying.
College Physics 101 and lab really explained practically it all as far as understanding electricity.
As soon as you understand the circuit
, you will never fear electricity again
, only respect it
is the greatest insulator
there can possibly be.