The 13 numbers are conceptualized similar to a pyramid. From numbers 1 to 7 we are climbing with much effort. At the number 8 we are in a position where perfect harmony is possible and on the top of the pyramid, and 9 to 13 is directed downhill, creating more ease with the energies, as they are no longer so forceful in developing us. This varies slightly between men and women: for men, 8 is considered to be the top of the pyramid as they are considered to typically be more balanced physically and have to struggle more to reach the spiritual levels than women, where 9 is the top of the pyramid, where they are typically thought to be slightly less stable in the physical realms but have an easier time accessing the spiritual.
The foundation and base of the pyramid. Realization and transmutation. The magic of being able to change and create, Governs all the other numbers.