The term "pipe dream"?

Question

where did the term originate and why is it called a "pipe dream" why those words?

Answer 1

Opium is smoked in pipes.  

Answer 2

A pipe dream is a fantastic hope or plan that is generally regarded as being nearly impossible to achieve

Answer 3

When you see through a pipe, your scope of  vision is very limited and you are not able to see other matters surrounding it. Similarly in a so called pipe -dream, you hope or plan for some goal, without considering other matters that can have a bad influence on it and bring about a total failure.

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