It was a fine day for it. The sun was, as usual, on fire, but as it was many millions of miles away it did not have much negative effect on David.
"Can I help you?" the traffic warden asked.
David gesticulated wildly at a nearby postbox. "It took my cash! Damn thing took my cash."
"Not to worry sir," assured the traffic warden, reaching for his emergency bowl of pasta which he kept for such situations. "I'll have it out in a jiffy." He poured the bowl's contents into the postbox, and within moments the postbox had spat out exactly five cubic centimetres of sugar cubes. "There we go."
David stared at the warden. "What do sugar cubes do to help me?"
"Nothing much," said the warden. "I just really like sugar." This did not have much of an effect on David, so the warden picked up one of the cubes and handed it to him. "Here, try one."
David did so, hesitantly. The sugar cube rolled around his tastebuds, becoming several times more delicious every second. "This," he concluded, "is really nice sugar."
It was at that point that a large van came into existence and crashed into the postbox, destroying it forever. Shards of broken postbox flew through the air, carrying letters, sugar and a couple of pieces of coinage with them.
David spent the rest of his life looking for every postbox in the world, feeding pasta to each one - but he never again got the chance to taste that delicious postbox sugar.