To me, the sabbats are celebrated for exactly the reason you mention, Baiombi, to honor significance of each stage of life. Every sabbat, every season, is glorious for what it contributes to the whole. The Wheel of the Year shows us the value of balance. Within the wheel of the year, with sabbats to illuminate the changes, there is also the lunar cycle, with esbats to illuminate the more subtle but personal energy shifts. Then within the lunar cycle, we have our days and nights, the shifting that is closest and most easily felt. From large to small, around and around, energy is dynamic and changing, just like our lives.