I wasn't really "around" when it came out, so I don't know, but I do know that it's frequently analyzed or referenced in the academic world. It's a wonderful film in that its components can be twisted around to fit just about any conception of reality ever developed; from Plato's Allegory of the Cave to an allegory of the Lacanian Real.
Although I haven't read a ton about the concept, I have read some of Phil K Dick's writings on the subject, and I do find the stuff fascinating.
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“It takes considerable knowledge just to realize the extent of your own ignorance.” ― Thomas Sowell