Useless things

I'm wondering about phrases that mean attempting to do the impossible. "Whipping a dead horse" is a good one, though it refers to something (whipping a horse) that *would* have worked once, but no longer will. "Getting blood from a stone" is another phrase.

Do you have some other good ones? Thanks. - Patty

I'm feeling musical today...

IT'S IMPOSSIBLE

It's impossible . . .
Tell the sun to leave the sky,
It's just impossible . . .
It's impossible . . .
Ask a baby not to cry,
It's just impossible . . .
Can I hold you closer to me.
And not feel you goin' through me,
Split the second,
That I never think of you,
Oh! how impossible . . .
Can the ocean keep from rushin' to the shore?
It's just impossible!
If I had you, could I ever want for more?
It's just impossible!
And tomorrow , should you ask me for the world,
Somehow I'd get it . . .
I would sell my very soul,
And not regret it . . .
For to live without your love,
It's just impossible!

Impossible! ( hmm )
Impossible!
Original music with Spanish lyrics by
Canache Armando Manzanero, 1970
with English lyrics by Sid Wayne

I think you're flogging a dead horse with this one.

These sayings concern doing something impossible, but each has a specific message--it's about something else:
You can't eat your cake and have it too.
The leopard can't change its spots.
You can't teach an old dog new tricks.

There is one that came up recently. "Catch lightning in a bottle." Not impossible. But very difficult. It means (I think) to harness creativity.

You can't squeeze blood from a turnip.

To expand the subtheme of futility... that's about as much use as "an ashtray on a motorbike", or "a one-legged man in an ass-kicking contest", or the very British "a chocolate teapot".

Screen door on a submarine. And the venerable "teats on a boar hog."

Here's another. You can't make a silk purse from a sow's ear.