La fin au début

What does this song mean? For my whole life I don't know what this song means. I mean, 'Should old acquaintance be forgot". Does that mean we should forget old acquaintances or does it mean if we happen to forget them we should remember them, which is not possible because we already forgot them?
~ Harry

Well, maybe it just means that we should remember that we forgot them or something. Anyway, it's about old friends.
~ Sally

Old years begat new years. For friends young and young-at-heart, new and longtime, here's to making our marks significant and meaningful and deliberate on the blank page that is 2012.

Skål!

Chin chin!

Cheers!