Aboleths have seen the rise and fall of worlds, apocalypse upon apocalypse. They are old past understanding, and their origins predate the current cosmos in which mortals (and their gods) erroneously believe they are so central.
Aboleths are effectively immortal and, barring death through accident or violence, continue to grow over their endless life spans, though after one reaches Huge size, its rate of growth slows so that changes can be noted only over geologic time.
It’s said that each contains the entire racial memory of every aboleth in its particular blood lineage that lived before it. However, recovering such knowledge isn’t an automatic process—older memories become accessible to an individual aboleth only as it ages, and then only with the aid of memory-boosting alchemicals and accompanying rituals.
The scattered, lone aboleths that currently creep in dark, watery places of the world are not of the lineages that make up the Sovereignty. Although it’s possible the ancestors of lone aboleths once served as its scouts, explorers, or agents, such connections have been lost to time. Thus, not every aboleth in (and under) Faerûn is necessarily an emissary of the Sovereignty. In fact, some might work at cross purposes with Xxiphu.