I do not know from whence comes this notion of passage of time adversely
affecting Avalonians... old age as a gateway to decripitude? That defies
Avalon logic! If anything old age brings greater potency; aging is an entirely
experience. At least physiologically... in this wondrous land.
So no, there will be no negative side-effects of getting old. Not even if
you're 508 - Zaphod's age - Avalon's oldest mortal.
Written by my hand on the 19th of Mournsend, in the year 1256.