My teacher pointed out that the Minoans were very interested in nature (as evident in their art, which often depicts animals and plants) and used opium. And I think one could even (jokingly) say that the bright colors in some of the frescoes (like the hills in the Spring Fresco from Akrotiri, Thera, before 1630 BCE, shown above left) are "psychedelic."2
I don't mind the hippie comparison, especially if it can help students to differentiate between the Minoan and Mycenaean civilizations. I do think it's important, though, for students to know that the comparison isn't perfect. For example, the fact that the Minoans had fortifications (despite what Sir Arthur Evans argued) and were possibly involved in human sacrifices suggest that these people weren't all about love and peace.

1 Mary Beard, "Knossos: Fakes, Facts, and Mystery," in The New York Review of Books (August 13, 2009). Available online here.
2 However, I only make the psychedelic comparison with students as a joke. It has been noted that the bright colors of the rocks are actually quite naturalistic. "The colors may seem fanciful to us, but sailors today who know the area well attest to their accuracy, suggesting that these artists recorded the actual color of Thera's wet rocks in the sunshine, a zestful celebration of the natural world." See Stokstad, Art History, 4th ed. (Upper Saddle River, New Jersey: Prentice Hall, 2011), 92.