There’s a common misconception, the book I’m reading now suffers from it, that single-user mode on a unix such as mac os x gives you root access. Actually, it grants you higher access than root. For example, set the immutable flag on a file (schg I think, but my iPhone doesn’t have man). Root can’t remove the flag, but the single user can.
OOP the Easy WayObject-Oriented Programming the Easy Way: a manifesto for reclaiming OOP from three decades of confusion and needless complexity.