Anything that is worth doing has been done frequently. Things hitherto undone should be given, I suspect, a wide berth.

All fantasy should have a solid base in reality.

What's done can't be undone.

To mankind in general Macbeth and Lady Macbeth stand out as the supreme type of all that a host and hostess should not be.

Anything worth doing is worth overdoing.

A thing well done is worth doing.