Another German - English translation

I'm afraid I cant get the gist of this. Can anyone out there in Toytown land help me?

Oh Mensch, der du dieses je gelesen
Wenn du einmal nicht mehr gewesen
Dann wirst du nie und nimmer mehr
Und wünschtest du es noch so sehr

Ta!

Rough and ready -
Oh you who are reading this
When you no longer exist
then you will be not be for evermore
No matter how much you wish for it.

That is a really crap translation but I think it gives the feel for it.

A bit like

Remember me as you pass by
As you are now so once was I
As I am now so you must be
Prepare for death and follow me

Maybe it's some kind of atheist's ode? Dead is dead and you're never coming back. The end.

Sounds good Steven. Thanks a million.

I've no idea what it is but it was written by Kurt Schwitters