The classic sentences about the impermanence of life are as follows:

1. Life is like a dream, and the world is like smoke. Dreams leave no trace, and smoke disappears without a trace. Those things that we once thought we would never forget are forgotten by us in the process of never forgetting them.

2. Things in the world are impermanent and human relationships are like dreams. Only by grasping the present can we live in the present.

3. Life is short and things are unpredictable. We cannot predict the future, but we can cherish the present. Only by grasping every moment can life be more fulfilling and meaningful without leaving any regrets.

4. Things are unpredictable and life is like a play. We are all the protagonists in the play, acting out our own joys and sorrows.

5. Life is unpredictable, every parting may be an eternal farewell, and every encounter is worth cherishing.

6. Things are impermanent and life is short. We must cherish every moment and let life shine with its most beautiful brilliance.

7. In life, things are unpredictable. Only by maintaining a normal mind can we cope with all changes.

8. Life is like a dream, and things are impermanent. We must learn to let go of the past, cherish the present, and embrace the future.

9. Things are impermanent, life is like a song, and we are all singers of life. Facing the ups and downs of life, we must use the most beautiful melody to interpret the story of life, so that the song of life can shine with moving brilliance in every moment.

10. Life is short and things are impermanent. We must learn to be grateful for every encounter and cherish every present.

11. Life is full of changes and things are impermanent. We must learn to be strong in the wind and rain and shine brightly in the sunshine.

12. Things are unpredictable and life is like a drama. We are all the protagonists of our own lives and we must live our own wonderful lives.

13. Things in life are unpredictable. We must learn to put down tedious affairs and pursue inner peace and tranquility.

14. Things are impermanent and life is short. We must cherish every moment with our loved ones and let family affection become the warmest harbor in life.

15. Life is like a dream, and things are impermanent. We must learn to cherish the present, embrace the future, and let life shine with its most beautiful brilliance.