I was working in a car parts supplier some many years back and this kid (very obviously a new apprentice) came in and asked for a "tin of compression". One of the old hands told him "It only comes in plastic these days, but it is the same stuff".

He trotted out the back, grabbed a small plastic jar, blew some cigarette smoke into it and sealed it. A hand written label and back to the counter.

Paperwork finished and the boy trots off.

A week later his boss rings up demanding to know what the **** was the idea in charging him $150 (or whatever the price was) for a "Small Jar of Compression". It was explained to him, and instead of losing his rag, he laughed and said "I know exactly who to blame for that. "

Three days later, the foreman from that shop came in to pay for the invoice. He told us that it was that or lose his job. We fixed it for him, but there was never another order for "compression".