Crumb blindness is a genetically transmitted condition which expresses itself similarly to haemophillia; both males and females acn be carriers, but it only exhibits itself in males.
Sufferers from crumb blindless are unable to see the mess left in food preparation areas as a result of the hasty assembly of snack foods, especially when this occurs during intervals in televised major sporting events.
The result is a kitchen strewn with torn-open bags and packets, carelessly discarded dirty cutlery, and crumbs everywhere.
When confronted with the "evidence", the sufferer from crumb blindness will profess genuine astonishment, having been completely unaware of the effects of their activity until it is drawn to their attention by their (usually female) partner.
Crumb blindness in females is extremely rare, and the subject of special study; in males, 100% of the population carry the gene, and it is expressed to some extent in over 70% of adult males.
There is no known cure, but single males tend to suffer more than those with long term partners.
"Christ ! Look at this place ! How much mess does it take to make one sandwich ?"
"Sorry, hun.... I just didn't realise......I think I have crumb blindness"