The Incredible-is-it Edible Egg?

I love this, and have to repeat it every time i reach for those powerful bursts of protein in those fragile little shells:

(a great rule of thumb when determining freshness of eggs), thanks to my friend David!

If not sure you ought-ter,
then place it in water.
If it lies on its side,
then it's fresh; eat with pride.

After three or four days,
at an angle it lays.
But, it still is a treat,
so go on and eat.

Ten days, stands on end,
in your baking 'twill blend.
'Cause it's definitely edible,
in your baking, incredible.

But, if it floats on the surface,
that egg serves no purpose.
'Cause a floater's a stinker!
Out the back door best fling 'er!