It's the first movie I remember going to see (at a drive-in theater when I was 7). It was kind of a flop when it came out, but it's achieved a certain cult status for its surprisingly deep philosophy on fear, self-realization, and facing mortality.
A lot of lines have snuck into my regular vocabulary. Flibbertigibbet, I'm not arguing that with you, I'm soul sick and you're gonna see that, brain cloud, I have no response to that...