In case there was any doubt, let me establish my grumpy bona fides: I don’t understand why anyone would wait in line for a fast-food hamburger.

But I certainly know how nostalgia for the foods from your past can do a kind of back-and-forth dance with your current food preferences, and when they come together in the same bite you may experience a kind of bliss. At least, that’s what I assume is happening with all those people who queue along Peachtree Road in front of the new Buckhead Shake Shack.

This fast-food burger mecca started small in New York — a park kiosk — and now seems intent on taking over the world. With outlets in Doha, Moscow and Boca Raton among other hamburger-loving corners of the globe, the company is preparing for an initial public offering that financial analysts say could go as high as $1 billion.

The menu features a few outliers but banks primarily on the holy trinity of burgers, fries and shakes.

The signature ShackBurger comes with cheese, lettuce, tomato and a version of the pink sauce that fast-food giants introduced to lure us away from the ketchup and mustard of the backyard patio. If you get a double ShackBurger you will find yourself in the same wheelhouse as McDonald’s double Quarter Pounder with cheese, or if you prefer, a Burger King Double Whopper with cheese or an In-N-Out Double-Double. It is your pink, cheesy handful — as high as it is wide.

Shake Shake distinguishes itself by using ingredients such as hormone-free, source-verified Angus beef for the burgers and fair-trade coffee for the shakes — foodstuffs that promise not only to be more responsible but also to taste better than those served at the typical drive-thru.

The restaurants themselves are built largely from sustainable and recycled material, further assurance that, no matter how big this company grows, it will try to avoid the environmental woes associated with the rapacious build-out of fast-food outlets.

But the whole enterprise rests on nostalgia: that warm sandwich served in a paper sleeve, the double stack that once upon a time changed the way we thought about hamburgers.

I would invite everyone at this point to think about the first time you considered the difference between the sturdy, fat burgers of yore and the layered, softly cheesy and pink-sauced fast-food burger stacks.

I’ll admit to being a strange child. When my parents took the kids to McDonald’s, I never ordered a burger because I was so smitten by the Filet-O-Fish sandwich. I remember thinking it was unfair you couldn’t get a double.

But at one point in my 20s, when I was between jobs and living in a new city, the Double Whopper became my best friend. I remember that first ravenous bite: the wash of hot meat juices, the cool flurry of iceberg lettuce in its pool of creamy pink, the sigh of cheese melting over and between, lubricating everything. It all sort of slid down, barely chewed.

The ShackBurger does try to re-create this specific experience, but also to better it. For starters, each burger is a beautiful construction, the draping, melty cheese slices angled just so, the lettuce frill peeking out from the bun, the whole thing served face up on the tray, an invitation to get lost in its soft awesomeness.

The patties are loosely formed, ragged at the edges, with a definite beefy flavor. The American cheese is its plasticine self, the sauce lavish, the bun as soft as a cotton ball.

I personally enjoyed the first couple of bites, but soon found the whole enterprise too slick and squishy in my hands. I didn’t like it as well as the burger stacks at Holeman & Finch Public House and Bocado, which have the pricklier flavors of mustard and pickle I crave as a counterweight to all the soft, fatty cheese and meat.

But I really don’t like any of them as much as a backyard grill burger, slightly bulbous, crusty on the edges, a bit bloody in the center — the kind of burger that serves as a pedestal for fresh garnishes and sharp condiments and where (heresy to some) cheese is optional.

As much as this makes me feel old and cranky to admit, I’m afraid I outgrew the fast-food burger stack, and I’d never stand in line for one.