When others celebrate with their families, they look back and see that their lives are not satisfactory (they are terminally ill in their dreams), they have not got the girl they like, and they are ashamed of their dead ancestors (grandmothers). This clue just links three things together.
It's just a sad mood on the occasion of the festival. It is difficult to detect during the day, and free association in dreams reflects the sad psychology.
-Subconscious Analytical Psychology Interprets Dreams