>>>The above paragraph is a random pick from what I say to anyone saying that we geeks talk our tecnho jargon and introduce our own words into common language. Now it was OK for blacksmiths, horseriders, railroad guys and seamen to do that, and somehow only we get criticized when we do the same thing.
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>>Aw, you're just blowing smoke. (where did that one originate?)
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>Blacksmith to his apprentice? Pump it up...

My guess would be a relationship to a magic show, where smoke is often used to deceive or help the deception.