As high school seniors locally and across the country steel themselves for what lies ahead after graduation, it's worth looking back to the film to which all subsequent slice-of-life, cusp-of-adulthood films about the end of adolescence owe a DNA-level debt: 1973's “American Graffiti,” only the second film George Lucas ever made.

It's easy to forget, ever since George Lucas became GEORGE LUCAS, but before he made “Star Wars,” the kid from Modesto, California, was a brilliant independent talent who'd studied the works of French New Wave directors.

More importantly, Lucas found a way to use those stylistic tricks and narrative tropes to tell the most American of stories, that of suburban teens at the outset of the rock-and-roll era, contemplating their onrushing adulthood.

It's hilarious to look back and connect the cavalcade of name-brand actors who populate this film's cast, who have since grown much older and more distinguished, with their baby-faced counterparts, back when guys like Ron Howard and Richard Dreyfus had buck teeth and full heads of hair, and future stars like Harrison Ford were mere bit players.

It's the last night of summer vacation in 1962, before best buds Curt (Dreyfus) and Steve (Howard) head off to college together, with the hopes of leaving their sleepy hometown of Modesto behind for good.

But before they go, Steve has to break up with his girlfriend Laurie (Cindy Williams, future costar of “Laverne & Shirley”), and Curt — an obvious authorial stand-in for Lucas himself, who's already developed second thoughts about leaving home — falls in love at first sight with a beautiful blonde he spots driving a white 1956 Ford Thunderbird (Suzanne Somers, future costar of “Three's Company”).

Anyone who's ever seen any other all-in-one-night film about That Last Wild Party Before We Have to Grow Up — especially if it was 1993's “Dazed and Confused,” or “Can't Hardly Wait” in 1998 — will recognize the almost anthology-style shifting perspectives in “American Graffiti.”

The seriocomic scenes cross-cut throughout the night, from Steve, to Curt, to drag-racing stud John Milner (Paul Le Mat, whose blue-eyed smolder still lives up to the standards of the onscreen heartthrobs who followed him) as he cruises down the strip, to Terry “the Toad” (Charles Martin Smith), an endearingly out-of-his-depth dork who's trying to impress his hot but bubble-headed date, Debbie (Candy Clark).

As much as this film functions as an archaeological artifact of a very specific time and place in American history — it was deemed “culturally, historically, or aesthetically significant” by the U.S. Library of Congress in 1995 and selected for preservation in the National Film Registry — it's also a timeless statement about the looming anxieties and whirlwind passions animating every generation of kids.

Even as adults, the reason we wax so nostalgic about adolescence is because, while the maturity we've hopefully gained in the years since helps us see how fleeting and trivial our concerns were back then, we can still remember when they felt like the fulcrum points of everything that mattered in our lives.

That bittersweet respect for the starry-eyed passions of adolescence is reflected in the real-life radio DJ, Wolfman Jack, playing himself for the film, as he agrees to send out a dedication over the air to Curt's mystery blonde.

All the teens in town are shown mythologizing Wolfman Jack as this globe-trotting outlaw, and the big man himself is more than happy to help build the legend, because he knows his outsized persona might inspire them to dream big dreams and do even bigger deeds.

“There's a great, big, beautiful world out there,” Wolfman Jack tells Curt, encouraging him to make his flight to college in the morning. “And here I sit, sucking on popsicles.”

As a former disc jockey myself, I know that feeling.