After laying down the scriptural foundations for this talk, Sayadaw explains that mindfulness does not occur alone: it has companions, namely, ardent effort & clear comprehension, as well as concentration.
Nature teaches us so many things about the nature of reality, including how profoundly interconnected and interdependent we are with all life. By sensing this directly, it profoundly shifts and dissolves belief in the reality of a separate, independent self.
Using the Buddha's advice to his son, Rahula, on developing different types of meditation, starting with meditating on the earth element internally and externally, and meditating "like the earth."