A railroad switchman working the yard one winter day went inside the train house to warm a bit while work was slow. The boss spied him inside and asked gruffly what was he doing in there, when the work was outside? The switchman replied that his feet had gotten very cold and he thought he would try to warm them while there wasn't much going on.
"Tomorrow you need to wear two pairs of socks if your feet are so prone to get cold" the boss said, unsympathetically.
"Well," the switchman replied dryly, "if two pairs of socks are warmer than three, I'll take one off."
Well, I thought it was funny....
The real Switchman told me that one last winter. Of course, he told it as a true story but I suspect it is just one of the old standards that exists in many of the trades.