I don't know if George Lucas really knew what he had in this picture--surely the script seemed funny enough, and the thought of the cars and the period music was enticing--but did he really know these "unknown" actors who bring these characters to life? It seems almost a fluke, shot in 29 days and on a tight budget, but "American Graffiti" is a four-star classic. It is perhaps pure nostalgia, mixing pathos and humor, sadness and craziness, hope and reflection, in quiet little bursts of excitement. After cruising with Milner all night, teenage Carol hates to say goodbye but does, waving from her porch with the light on; Toad survives one bad accident after another, but his real moment is in hearing praise from his date (fantastic, husky-voiced Candy Clark, dolled up like a speeding Sandra Dee) just before she says good night; after chasing his dream date all night, Kurt (Richard Dreyfuss, green and anxious, and appealingly bemused) finally gets to talk to the stunning blonde wonder on the telephone, where she whispers a wrenching goodbye. The whole movie is steeped in reflection. It has great, great humor, yet it leaves one with a bittersweet melancholia. For yesterday is in the past, with our music, our memories, and our hesitant farewells.