12-31-11 Auld Lang Syne and Happy New Year

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

Should auld acquaintance be forgot 

And never brought to mind? 

Should auld acquaintance be forgot, 

And auld lang syne?

For auld lang syne, my jo,

For auld lang syne,

We'll tak a cup o' kindness yet,

For auld lang syne.

And surely ye'll be your pint-stoup,

And surely I'll be mine;

And we'll tak' a cup o' kindness yet,

For auld lang syne.

For auld, etc. We twa hae run about the braes,

And pou'd the gowans fine;

But we've wander'd mony a weary fit,

Sin' auld lang syne.

For auld, etc. We twa hae paidl'd in the burn,

Frae morning sun till dine;

But seas between us braid hae roar'd.

Sin' auld lang syne.

For auld, etc.And there's a hand, my trusty fiere!

And gie's a hand o' thine!

And we'll tak' a right gud-wellie waught,

For auld lang syne.

~Robert Burns 

 and if that's too much Scottish for ya... 

Should old friendship be forgot'

And never remembered ?

Should old friendship be forgotten,

And days of long ago.

And surely you will have your tankard !

And surely I will have mine !

And we will take a cup of kindness yet,

For days of long ago'

We two have run about the hills

And pulled the daisies fine :

But we have wandered many a weary foot

Since days of long ago.

We two have waded in the stream

From dawn till dinner-time :

But seas between us broad have roared

Since days of long ago.

And there's a hand my trusty friend !

And give me a hand of thine !

And we will take a large draught

For days of long ago.