The surface meaning suggests a way of existing within the material realm while maintaining a detachment from its allure. It implies navigating daily life, fulfilling responsibilities, and interacting with others, yet not being wholly consumed by worldly desires, possessions, or social constructs.

The deeper Buddhist teaching, however, points towards understanding the nature of dukkha (suffering) inherent in all conditioned phenomena. The Buddha taught that the world, as perceived through our senses and ego, is largely an illusion (maya), a construct of impermanent elements. To be "not of the world" is to realize the anatta (non-self) and anicca (impermanence) of all things. This realization liberates one from the cycle of craving and aversion, the very engines of suffering. It's about seeing through the veil of appearances to the underlying emptiness, thereby achieving nirvana, a state of profound peace and freedom from the bonds of existence. This isn't about ascetic withdrawal but a radical shift in perception, akin to observing a play without identifying with any character.

In your life: Practice mindful observation of your reactions to external events, recognizing them as fleeting mental formations rather than absolute truths.