A man walks up to his place of employment. He finds the shutters almost closed, yet he needs to get inside. A strange man is standing near the doors on the other side. Fortunately, a familiar colleague is standing next to him. The man outside motions to the strange man to get his colleague's attention. The strange man grimaces, shrugs off the man's polite, clear request with a "can't help ya, mate" glance, before resuming his stupor.
The man outside reiterates his request, this time more forcefully. To the delight of the excluded man and, indeed, common sense, his colleague turns, and sees him. He is, finally, granted entrance. Shortly thereafter, the rude man gives the inconvenienced man and all of his colleagues a lecture on appropriate behaviour when dealing with dodgy types. In particular, the rude man emphasizes the benefits of a polite, friendly demeanour.