I should add, I've spent much time in front of a white board drawing the system and explaining it to Observers/TFOs along with all the other systems so it seems simple to me, the units I've worked at have such training as a compulsory requirement at the end of each shift briefing so that all flight crew are conversant with what the emergency captions really mean, rather than just repeat what the emergency drill cards say without knowledge.
In fact the Chief Pilot often requires pilots under test to brief systems to TFOs in his presence as a real test of the pilots understanding.