You can’t drink out of a glass half-empty; emptiness has no taste. A glass half-full is half-full with water to cool you down, to perk you up, but above all, to sustain you till the next time you need it again. Drinking half-emptiness nourishes nothing.
There is emptiness in a glass, but only when there is emptiness in a glass can you fill it up. A solid glass cylinder cannot hold anything, and any attempt to fill it up results in a mess and a whole lot of wasted water. But by recognising that a glass can be empty can one begin to impart some salve in it.
Why fill up a glass to the brim? What use is there to beat all emptiness out of a glass? Even the steadiest of hands are bound to slip up, and spill. It is fine if a glass still has emptiness in it. After all, you didn’t pick up a glass for its emptiness, did you? You picked it up for its what it’s filled with.
So quit griping about half-emptiness and drink out of your half-fool cup, you full.