The entire range of non eternal joys has been set out before him by yama, who can give it to all of this. Whether or not these things will remain the next day, next moment, we have no idea. Even if you promise me long lit, and you do give me long life, one day will come for me, and that'll be the last day of my life. That's how normal, ordinary life goes on. Death comes its its inevitable.
Swami Sarvapriyananda teaches the Katha Upanishad, which is one of the most popular Upanishads. The scripture concerns the story of a young man who goes to the house of death to find out what happens after death. The reply describes the nature of reality and the meaning of life.