A key idea in the Buddha's teachings is that everything changes. When we have a lovely moment or a lovely friendship or there is a lovely sunset, we have a natural tendency to want to preserve that loveliness. It is natural for us. We want to stay alive, to stay happy, to stay in charge. We want things to be as they are when we like them and only to change when we don't. Buddha warned people that they had a natural desire to hold on things but that desire is not going to be satisfied very often. Moments pass, friendships pass, sunsets lead on into night.
The poem by Theodore Tilton "This, Too, Shall Pass Away" is a good one for a lyrical tour of the many aspects of our lives. Lynn wrote a poem about after this or after that, there is another day, a new deal.
Charlotte Beck emphasizes that the good of life comes from the constant change, the steady renewal, that life is life only with change, death, new days, new life. With training or without it, we are not going to be able to steady embrace change. We are going to want some things to stay as they are. Noticing our wants and accepting them and temporary aspects of our lives and the good things in them may help.