A colleague offered my partner and I a place in the country to retreat to plan the whole campaign. We travelled 400 miles by bus, train and leg-power to an idyllic cottage miles from anywhere and started work. The nearest town was an hour's hike away, the nearest phone box 30 minutes cross country, the sun shone, we were amazingly productive... and I got all the art work for the publicity campaign finished well ahead of schedule.
So I hiked into the village with all the original art on my back, bought hardcore packaging materials to protect it, and queued in the postoffice to send it to Jim, our publicity coordinator, back in the city. To make sure that it got there I paid for guaranteed Next Day Delivery at huge expense.
Walked to the phone box the next evening to call Jim and find out what he thought of the art. It hadn't arrived.
Nor the next day, or the day after, or the day after, or the week after. The postoffice claim to have no knowledge of it, the printer's deadline is approaching...
So I sit up all night to re-ink the art, cut short the retreat, walk, train, bus back to the city, and hand deliver the artwork to Jim.
As I approach Jim's door I pass a furtive looking postman. In Jim's letterbox - a mashed and screwed up tube with a familar looking label. Rather than ring the doorbell - and I can see Jim through the window - the postman has hammered it flat and into the slot.
TL DR - Apparently the UK Postal Service believes a "Guaranteed Next Day Delivery", marked "Fragile Do Not Bend" translates as "mangled tube of shredded paper forced through door 10 days late at a speed only slightly faster than a starving artist on foot"