Personal law is simply the thought that controls your mind and your life more than any other thought. Finding that thought is the most valuable knowledge that you can have about yourself. It is like the leverage on personal change. It enables you to change very efficiently.
"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.