What is inner impermanence? The term “inner” denotes sentient beings. The sentient beings referred to here are not plant life but living beings that can experience suffering and happiness.
Inner impermanence can also be classified as continuous or momentary.
Continuous impermanence is easy to understand, like when we undergo successive rebirths as a human or god in the previous life, as a human in this life, and as a human or animal in the next life; or when we experience the various changes within this lifetime, i.e., birth, infancy, childhood, youth, manhood, aging, and death. These changes which we can clearly observe not only in ourselves but also in other beings constitute continuous impermanence.
~Depicted from THE FOUR SEALS OF DHARMA - All Composite Phenomena are Impermanent