I don’t know how many times I’ve watched “Casablanca.” Is it 20? Or 30? Could it possibly be as often as 40?

I watched it again last week. In its entirety. Yet again.

What is it about this movie that remains so compelling and watchable over so many years and through so many viewing?

It has to start with the writing, the brilliant and witty dialogue crafted by the Epstein Brothers, Julius and Philip.

I ventured online looking for “Casablanca” quotes and found some on IMDB.com. Well, more than some. I hit print and the pages kept furling out of my printer. And kept furling out, one after the other and yet another.

I was shocked – shocked! – when the printer stopped spitting out and I had a nice, thick stack of white sheets with black type. It came to 12 pages of quotes from what has to be the greatest screenplay dialogue ever written.

Here’s a sampler:

Rick: “Of all the gin joints, in all the towns, in all the world, she walks into mine.”

In that “gin joint” is the following timeless encounter between Rick and Captain Renault:

Rick: “How can you close me up? On what grounds?”

Captain Renault: “I’m shocked, shocked to find that gambling is going on in here!”

At that moment a croupier walks over and hands Renault a wad of cash.

Croupier: “Your winnings, sir.”

I can’t and won’t re-type all 12 pages of dialogue I printed out because it would take too long and nobody would want to read it all and there may be some legal restrictions on essentially copying the entire screenplay.

What the heck, here’s one more example, an encounter between Rick and the oily Ugarte, played by Peter Lorre.

Ugarte: “You despise me, don’t you?”

Rick: “If I gave you any thought I probably would.”

Everything came together on this movie, perhaps as seamlessly as any movie ever made.

The perfect cast with just the right actors for the right roles. Humphrey Bogart and Ingrid Bergman in the leads, of course.

Then all the rest.

Claude Rains as Renault. Paul Henreid, Sydney Greenstreet, Conrad Veidt, Lorre.  The smaller roles of refugees trapped in Casablanca were played by actors who in real life were actual refugees from Europe.

As the late and great Roger Ebert wrote, “No better cast of supporting actors could have been assembled on the Warners lot. …”

So many elements make this movie my favorite.

Good triumphs over evil. The historical flavor of the story set just before we became embroiled in World War II.

Rick’s motivation to get involved requires a little basic historical knowledge of that era that is becoming increasingly rare in our ahistorical society. Part of Rick’s backstory is his fighting in Ethiopia and Spain against fascists. Not many people now know that Mussolini invaded Ethiopia and the Spanish Civil War was a proxy and warm-up for what was to come.

But it’s more than writing and acting and a sense of time and place that make “Casablanca” special.

Dooley Wilson’s brilliant piano playing and singing of “As Time Goes By” is still beautiful.

The emotional impact of “Casablanca” scenes still resonate after dozens of viewing. Anybody untouched by the café scene where Laszlo leads the room in singing the “Marseillaises” and drowning out bombastic Nazis has to be either a Nazi or a communist or an apolitical sociopath.

Laszlo orders the band to play the Marseillaises while the Germans bellow out some militaristic song.

“Play it,” he says to the band.

The band, after getting a nod of approval from Rick, strikes up the French song, the patrons of Rick’s stand and sing, letting the Nazi thugs know they won’t win a contest of national songs in Rick’s and by implication they won’t win the war.

There’s also so many subtle filmmaking things going on here, things I haven’t always picked up, things crafted by director Michael Curtiz, things that make the story hum.

Look for scenes where glasses are tipped over on tables. Those glasses are nuanced storytelling devices, suggesting, well, I’m not exactly sure what but perhaps turmoil and coming change or uncertainty.

And that famous scene near the end when Curtiz cuts to close-ups of Rick and Ilsa and Laszlo on the tarmac is flawless. The quick cuts to faces and the hats are still magical more than 70 years since the movie’s 1942 release.

Now, far too many movies are about computer-generated images of monsters and superheroes and explosions and are aimed, it seems, at particularly slow-witted and violent adolescents. These movies lack humanity.

“Casablanca” oozes humanity out of every scene.

Film critic Leonard Maltin once wrote this: “Our candidate for the best Hollywood movie of all time.”

He’s right. Oh, I’ll watch “Casablanca” again. Count on it.

Soon. For the 21st or 31st or 41st time.

I’ve lost track.

But I will watch again.

As Rick says to Ilsa, “Here’s looking at you, kid. “

I’ll be looking and listening again.

“Major Strasser has been shot. …round up the usual suspects.”