Growing old is mandatory, growing up is optional.
Growing old or ageing is a natural phenomenon. One can age beautifully, gracefully or one can decay into an ugly creature, but ageing is inevitable.
Growing up on the other hand is a spiritual phenomenon, its a flowering, an evolution.
Growing old happens to all animals but only a Human Being can grow up. One can imagine our lives as being akin to a tree. As the tree grows higher it is essential that the roots grow deep.
Just growing old is exactly that, ageing, it grows but the roots are shallow, rarely good for anything or anyone, not even to its self as it struggles to survive a small storm or a setback. Whereas growing up is like a tree, with strong and deep roots. While it sways with the storm, it rarely ever collapses. Its strong, stable and blooms with vigour nurturing by providing fruit and protection to life in in its vicinity.
Sadly though this potential is available to all, only a few choose to grow up, the vast majority merely grow old. Eating, sleeping, mating they live dull and meaningless lives. That is why we are obsessed with seeking entertainment all the time. Unfortunately nothing can meaningly fill the life of an individual that is not growing up.
Whichever path we tread there is a subtle difference between those growing old and those growing up. They are both constantly losing friends and relationships. The first is frantic about this; the second is at peace.