Things are not clean. Even though soap and water have been applied, objects remain clogged with grease and protein, bacteria and mire.
Grease beads on a pan, coats a plate, overlaying knives and spoons. Grease does not like soap. Add soap and grease goes away, but with too little soap or soaks in water full of oiliness the grease hovers and swims. Grease prefers cold water to warm. The hotter the water, the less likely grease will remain.
Starch is another skin. It adheres carefully and craftily, defying efforts at its removal. It cannot be seen in the water. Water must be removed or scrubs must be soapy and vigilant in order to ensure it moves on to pipes. Left to its own devices, it curls and dries, affixed with tenacity.
The backs of implements used to eat and to prepare sustenance (plates and bowls, pans, glasses and cups) all need cleansing on their backs and under their bottoms. Material hides there, ignored by those who do not consider its existence.
Toilets with urine that is not flushed begin to smell acrid and pungent.
If a toothbrush is electric and removed from the mouth before it ceases rotation, it leaves small bits of bacteria and spit on all surfaces in its vicinity. Others who come into contact with these substances may share.
Why remove items from the floor when it is more simple to walk across them than to place them elsewhere?
Used toilet tissue does not replace itself.