A search for the origin of this expression, which means “…a fantastic hope or plan that is generally regarded as nearly impossible to achieve…” led me to todayIfoundout.com, a web site I don’t recall using as a reference previously. The site explains that the first written reference was in the Chicago Daily Tribune in an 1890 story about aerial navigation. “It has been regarded as a pipe-dream for a good many years.” The article explained that “…the true origin of the phrase… (is) a reference to the dreams experienced when smoking opium.”