Nowadays, though, I look at a menu and the dozen-odd drinks will all be new to me, which takes some doing: I’ve been writing about cocktails since 1999 and drinking them a lot longer still. If there’s a classic, it’ll have undergone a Shakespearean sea change. As for any original cocktails, they certainly are that. These will have five, six, seven or more ingredients, many of them obscure or house-concocted, and all combined in ways intended to startle. Say, marigold-blossom infused espadín mezcal mixed with Alsatian kirschwasser, Strega liqueur, house-roasted sweet-potato nectar, sercial Madeira and yuzu bitters. They’re built to say “hey, look at me!”

This isn’t automatically a bad thing. Some of these creations turn out to be truly delicious, and without a push toward the experimental, we would never have this spectacularly broad palette of ingredients, or fun things like ice diamonds and the so-called Coconut Blast. But balancing that many full-flavored ingredients has a high risk of failure. And, with that many variables in play in each drink, there’s no way of predicting whether my $20 is being advanced for something heady and delightful or something that tastes like water mopped up from a flower-shop floor.

So, what the hell happened? Clearly, a corner was turned, and somehow we went from bartenders playing reanimator with forgotten cocktails, to bartenders reimagining themselves as Michelin-starred chefs, creating tricky, impossible-to-replicate works of culinary art—but when was that, and more importantly, why?

To answer that question, it’s worth noting that we’ve been through this kind of change before. In fact, the history of the American bar, from its very beginning in the lean years after the Revolution, is one of irregularly alternating cycles of classicism, let’s call it, and creativity. Up until the beginning of the 20th century, these things were pretty regular: There’d be 20-odd years of bartenders turning out all kinds of elaborate, occasionally unhinged drinks, followed by another 20-odd years of their successors tidying things up, like keeping the good drinks and bouncing out the ridiculous ones. Take, for example, the Mint Julep with three kinds of wine plus French brandy, Jamaican rum, lemon, pineapple and powdered sugar. It was followed by the simple Brandy Julep, which kept the rum as a float and ditched the rest.

“Somehow we went from bartenders playing reanimator with forgotten cocktails, to bartenders reimagining themselves as Michelin-starred chefs.”

But by the time the mid-1960s hove into view, five long decades of deferred change burst out like a dam-break. When the baby boomers reached drinking age, they brought with them not only a wave of new drinks, but a tide that swept out most of the old ones. The young men and women (in unprecedented numbers) in bars weren’t there to acquire a taste for Scotch and rye or to appreciate a dry Martini made just so. They weren’t training to be grown-ups, like their parents had at their age, and there were enough of them to force the world to bend and meet them for a change.

So, in came easy, fun, youthful stuff like Harvey Wallbangers and Velvet Hammers, Godfathers, Pink Squirrels and Piña Coladas, and out went all but a few of the, dare I say, sluttier classics—the Sloe Gin Fizz, because it was sweet and pink; the Singapore Sling, because it sounded sexy; the Brandy Alexander, because it was sweet and creamy. (The Martini still survived, but only if you count the vodka Martini or the Martini on the rocks.) Dirt-simple was in. “Two ingredients to a drink seems to have become a golden imbibing rule,” the New York Times noted in 1966; use a light spirit like blended Scotch, splash in a little liqueur—Drambuie, amaretto, whatever—and done. Along with the stiff old drinks went the stiff old bartenders, the veterans who understood the traditional principles of mixology that guided how drinks were mixed, who knew the lore that made people want to drink them. Enter instead a mess of charismatic young college grads who knew how the kids thought and could be taught to bang out a few simple drinks. If they had career aspirations, they weren’t in bartending; they’d work the job for a while and then someone younger and, now, hipper would replace them. San Francisco’s pioneering fern bar, Henry Africa’s, placed an ad for bartenders in 1972 that said it all: “21-25 yrs., well proportioned 5’10” + … College degree required, experience not.”

By the 1970s, when everyone had gotten a little bored with this new mixology, bartenders didn’t back off, they doubled down. Once you establish that the game is novelty, it’s hard to stop that game. As the ’70s wore on, bartenders tried a bunch of things, including giving their simple drinks ever-smuttier names—e.g., Sloe Comfortable Screw, Screaming Orgasm—and whipping technicolor liqueurs, artificial fruit syrups and ice cream into an ecosystem of new, flamboyantly nonclassic, weakly alcoholized kiddie drinks. (The Mudslide is the main survivor from that cohort.) Some bartenders, on the other hand, leaned farther into the performance aspects of what they did. Dale Rosenberger of Edmonton, Alberta, took the cake by working the very busy bar at the Rex Motor Inn while hanging upside down from gravity boots.

By the late 1980s, Generation X, which followed the baby boomers the way the guy with the shovel and the wheelbarrow follows the elephant parade, had enough with these boomer shenanigans and started feeling its way back to something rather more traditional. It took a while, and a whole lot of Cosmopolitans and Apple Martinis, but by the late ’90s, forces were aligned to overthrow, or at least offer a widespread alternative to, the new mixology in all its branches.