When Steven Spielberg’s Jaws hit theaters back on June 20, 1975, the modern-day summer movie was born. One of the first films ever to be widely released on a large number of screens across the country on a single day, Spielberg’s sea-faring saga redefined what it meant to be a blockbuster. On top of all of that, Jaws also happened to be a rollicking, enjoyable, and insanely scary movie, mixing popcorn thrills and the kind of character development you tend to only see in Oscar-bait prestige films. In a new interview about Jaws with Ain’t It Cool News, Spielberg talked about his nerve-wracking months on the fictional Amity Island (actually Martha’s Vineyard), how he gathered his cast, and Robert Shaw’s infamous U.S.S. Indianapolis scene (oh, and a few words for the Indiana Jones and the Temple of Doom haters out there — hint: blame George Lucas). Here are some of the more excerptable excerpts.

On being unprepared to make a film in a real body of water, which stretched the shooting schedule way past everyone’s patience:

“I was naive about the ocean, basically. I was pretty naive about mother nature and the hubris of a filmmaker who thinks he can conquer the elements was foolhardy, but I was too young to know I was being foolhardy when I demanded that we shoot the film in the Atlantic Ocean and not in a North Hollywood tank. But had I to do it all over again I would have gone back to the sea because it was the only way for the audience to feel that these three men were cast adrift with a great white shark hunting them.”

On the malfunctioning mechanical shark:

“Everything on land went normal! … I was actually on schedule for the first part of the picture … The shark not working was a godsend. It made me become more like Alfred Hitchcock … When I didn’t have control of my shark it made me kind of rewrite the whole script without the shark. Therefore, in many people’s opinions the film was more effective than the way the script actually offered up the shark.”

On assembling his cast:

“Casting sometimes is fate and destiny more than skill and talent, from a director’s point of view. First, I went to see Lee Marvin and he said no. Then I went to Sterling Hayden and he said no. Then finally David Brown, who had just worked with Robert Shaw on The Sting, and said, ‘What about Robert Shaw?’ I said, ‘David, you’re a genius!’ And Robert said yes. That was a simple story, although it took six months to cast Quint, and I went to several actors before Roy Scheider. They didn’t turn me down, I just decided they were not right for the part. I tested dozens of possible Brodys. I don’t want to mention any names because many of them are still with us. [Then, Spielberg met Scheider at a party] Roy actually said to me, ‘You have such a glum look on your face. What’s the matter?’ I said, ‘Aw, I’m having trouble casting my picture.’ He actually said, ‘Who have you gone out to?’ I named a few names and he looked at me and said, ‘What about me?’ He actually said, What about ME?!? … I looked at him and said, ‘You’re right! What about you? Will you make my movie?’ Without even asking for a script he said, ‘Of course! If you want me, I’ll do it!’… And Richard Dreyfuss was my first choice.”

On Robert Shaw’s infamous U.S.S. Indianapolis speech:

“We shot it twice. the first time we attempted to shoot it Robert came over to me and said, ‘You know, Steven, all three of these characters have been drinking and I think I could do a much better job in this speech if you actually let me have a few drinks before I do the speech.’ And I unwisely gave him permission … I guess he had more than a few drinks because two crew members actually had to carry him onto the Orca and help him into his chair. I had two cameras on the scene and we never got through the scene, he was just too far gone. So I wrapped … At about 2 o’clock in the morning my phone rings and it’s Robert. He had a complete blackout and had no memory of what had gone down that day. He said, ‘Steven, tell me I didn’t embarrass you.’ He was very sweet, but he was panic-stricken. He said, ‘Steven, please tell me I didn’t embarrass you. What happened? Are you going to give me a chance to do it again?’ I said, ‘Yes, the second you’re ready we’ll do it again.’ The next morning he came to the set, he was ready at 7:30 and out of make-up and it was like watching Olivier on stage. We did it in probably four takes. I think we were all watching a great performance and the actors on camera were watching a great performance; Roy and Richard.”

On clearing up who actually wrote the speech:

“I owe three people a lot for this speech. You’ve heard all this, but you’ve probably never heard it from me. There’s a lot of apocryphal reporting about who did what on Jaws and I’ve heard it for the last three decades, but the fact is the speech was conceived by Howard Sackler, who was an uncredited writer, didn’t want a credit and didn’t arbitrate for one, but he’s the guy that broke the back of the script before we ever got to Martha’s Vineyard to shoot the movie. I hired later Carl Gottlieb to come onto the island, who was a friend of mine, to punch up the script, but Howard conceived of the Indianapolis speech. I had never heard of the Indianapolis before Howard … Howard one day said, ‘Quint needs some motivation to show all of us what made him the way he is and I think it’s this Indianapolis incident.’ I said, ‘Howard, what’s that?’ And he explained the whole incident of the Indianapolis and the Atomic Bomb being delivered and on its way back it was sunk by a submarine and sharks surrounded the helpless sailors who had been cast adrift and it was just a horrendous piece of World War II history. Howard didn’t write it as a long speech, he probably wrote about three-quarters of a page. But then when I showed the script to my friend John Milius, John said, ‘Can I take a crack at this speech?’ and John wrote a 10-page monologue that was absolutely brilliant, but out-sized for the Jaws I was making! But it was brilliant and then Robert Shaw took the speech and Robert did the cut down … Robert took a crack at the speech and he brought it down to five pages. So, that was sort of the evolution just of that speech.”

On what happened to Milius’ 10-page version of the speech:

“I don’t think it exists. I know I don’t have it. I’ve been asked for it, everybody has been wanting to see it and John doesn’t have it because in those days we didn’t have computers, we didn’t have hard drives, it was just on pieces of paper!”

On why he chose not to return for Jaws 2:

“I was done, I was done with the ocean. I would have done the sequel if I hadn’t had such a horrible time at sea on the first film. I would have absolutely jumped at the chance to own the sequel because I knew that when I was walking away from the sequel I was walking away from a huge piece of my life that I helped to create, but it wasn’t a hard decision to walk away from it. [But Spielberg adds that he has had ideas for a sequel since then…] “I have a very, very good scene which I thought would have been good for a sequel someday … every time I think of this scene, I think, ‘Hmmm, could this be another Jaws movie?’ And I have to immediately pull myself back down to earth.”

On all the Indiana Jones and The Temple of Doom haters (Spielberg has occasionally been one himself):

“Here’s the thing … for all the fans of Temple of Doom who think I beat up too much on it, those fans who beat up on George Lucas 24/7 at the drop of any fedora, I would just say please give George credit. He’s the one who made it dark, he’s the one that decided on the story and on the concept.”