Solomon had it all: wealth, power, knowledge, relationships,  fun.  Yet near the end of his life, reflecting back, he realized that none of those things, not even his life on this earth, will last.  “All is vanity.” 

He urges us to enjoy these things that God has provided (9:7-9), but to be aware that they, in and of themselves, are not what gives meaning to life.

All that lasts is God, and in some way not yet understood fully until Jesus’ Resurrection hundreds of years later, Man’s relationship with God.

His conclusion: “Fear (awe, reverence”) God and keep his commandments...”

(12:13-14)