from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A very long time ago, from the beginning or as far back as one can remember.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. as long ago as anyone can remember
The phrase may originate from a representation of the zeroth or first year of the Common Era CE, or the point between 1 AD and 1 BC (as there is no year 0). (Wiktionary)