I'm testing a training course for a customer, and it's automotive related (yay!). It covers general maintenance and the components that each "section" contains (engine, suspension, etc). I got to a section about automatic transmissions, and it says that unless you are an engineer or a specialized tech, don't worry about knowing how they work (pro tip: it's magic!). In the HVAC section, there are roughly 20 pages of the thermodynamic properties that govern how the friggin system works, and goes into things like absolute zero and the kelvin scale. Maybe I'm missing something, but I'd imagine an auto tech would find knowing how an automatic transmission works far more useful than retaking a high school science class.