During her 7.18 Oppenheimer screening in Burbank Sasha Stone was hugely bothered by a pair of 20something women who took out their phones around the half-hour mark and were pretty much texting all through it. They didn’t even turn down the brightness levels on their screens.

The first thing I texted Sasha when my Oppie screening ended last night at 10:20 pm was “as much as I condemn phone-surfing during a film and especially during a major blue-chip immersion like Oppenheimer, I understand why those women were texting.”

An unmistakably gradeA experience, Oppenheimer could be re-titled Oppenheimer: Interiors as it’s almost all super-smart dialogue, super-smart dialogue and more super-smart dialogue inside rooms (university classrooms, Los Alamos conference rooms, hallways, hotel rooms, dining rooms, the Oval Office).

Okay, the historic New Mexico test explosion of the first atom bomb (7.16.45. 5:29 am) happens under an open-air nightscape and there are several other moments that happen outdoors, but still…

The likely truth is that if you’re not at least half in love with the Oppie legend going in — if you haven’t done your homework by having seen The Day After Trinity (free on YouTube) and if you haven’t read “American Prometheus” — your Oppenheimer experience may (emphasis on this word) feel like a big fat Alaskan grizzly bear sitting in your lap, or certainly right next to you.

It feels (and is) long and demanding, and at three hours is certainly a proverbial tough sit. And yet it’s undeniably a firstrate, grandvision, smartperson movie that absolutely surges with the spirit of semi-tortured genius (I was reminded of similar-toned portions of A Beautiful Mind) and is highly charged in every respect and is even emotionally engrossing during the persecution-of-Oppie finale (kudos to the “junior Senator from Massachusetts” for voting against the venal Robert Downey Jr.!!).

And I adored viewing this Christopher Nolan film on that tall-as-an-apartment-building, super-sized IMAX screen (I was sitting third-row center), but I’m afraid I’ll need to re-watch it at home with subtitles as I fully understood roughly half of the dialogue, certainly no more than two-thirds. That or I’m simply too fucking dumb to keep up with all the density and complexity.

Not to mention the fact that my poor right knee was aching and moaning in pain as I had no place to shift or maneuver within that tight IMAX seating area, and my knee massages began around the 45-minute mark and never stopped…one of the most challenging IMAX screenings I’ve ever endured.

At the one-hour mark I looked at my watch and said to myself, “oh, dear Lord, this is so brilliant and dense and tightly woven and sharply focused to a fare-thee-well, and God help me but there’s another two hours to go!”

And man, the Ludwig Goransson score is really loud in portions, and certainly during the final act. It throttles and hammers you into submission.

HE to friendo: “You didn’t feel a tiny little ‘yay!’ surge when it’s mentioned that JFK voted against Downey? I did.”

Friendo to HE: “Naah, that was just a little fun grace note of JFK nostalgia.”