I am reasonably clever (degree etc) but I seem to have a mental block about everyday physics (not Sheldon Cooper level!) such as electricity, circuits, wiring and how it works so that DH will stop trying to be helpful and explain it to me - as this just causes minor disagreements 
I've previously tried the "Dummies" series but I'm after a more basic level I think - sort of secondary school level that presupposes no prior knowledge.
This all stems from a lingering fear I have of Christmas tree lights being on an extension cable - I have memories of a fire brigade advert about on overloaded plug catching fire; and as it's coming up to tree time I can feel my anxiety rising and my DH's sighing starting 