When meditating I use an App on my phone as a timer. When the timer elapses it rings a bell and a phrase appears on the screen. So for the last two years I have been greeted at the end of my practice by the words Anyone who understands impermanence ceases to be contentious. By this time I know the words of this ancient phrase very well. However, I realize there is a big difference between knowing the words and knowing this in reality. Sure, I know that things change, the seasons come and go, and mental states change frequently. But I still have a strong investment in things staying as they are. And so I struggle. And whenever we struggle with how life actually is we suffer to some extent. So it seems to me that we really need to experience change in a very real and personal way in order to learn what it means to accept it as a fundamental principle of life. And sometimes this is forced upon us when we lose something or someone dear to us, when we have to deal with illness or when we are with someone who is close to death.
Sooner or later we all have to work with things in our life that we wish were different. And distinguishing when to fight for something and when to let go is not always easy. However, ther are times when we have to accept the message from others or from life that there is nothing we can do. When this is the case we allow ourselves feel the sadness which these situations provoke because that is only natural and the pain is often substantial. And then we try to do what the wisdom traditions teach : the best response to things that are beyond our control is to work at not struggling with them. It is not an easy lesson to learn, and I find that this learning it is always ongoing. But it is the big challenge in this life, to become a knower of change and to let it teach us.