Permanence is a fallacy that arises out of our ignorance; mundanely from our perceptions of things. When we observe a chair, we think that it is there before, now and in an hour, the next day and perhaps in a month. The human mind than simply assume that the chair is permanent albeit on a certain time scale. We think that the chair is not important; whether permanent or not, how does it affect our lives? Hence, we say the chair is permanent! The same applies to the bubble, the dew drop, the lightning flash and the dreams or shadow, How does this apply to our lives?
If we examine our own lives closely, we can then relate the "permanency" of our bodies, our possessions, our friends, family, our thoughts, events in our lives and finally our lives. Then we can say that in reality things are impermanent. That is the truth because we experience it and we suffer because of it.
By realizing impermanence, we can change of expectations of things and events in our lives. Expect things to change, that the good and become bad and the bad and also become good and everything in the middle. We can choose to be very pessimistic or we can choose to become optimistic. We can take the necessary action to lead us to ultimate happiness. Practice the Dharma.
This realization has to lead one to take some action. Otherwise, what is the point?