I do agree that a large chunk of it is unnecessary for a PPL to learn, but then again I had to take an exam in in-flight catering before I could crew a Wessex!
I didn't very often serve ICAO Schedule 28 to my Passengers (continental breakfast) Why do useless facts like that stick in my head for 20-odd years, but trying to remember the VMC minima for different classes of airspace just passes in one ear and out the other....?(tonight's train subject - airspace)