Will Reiser and Seth Rogen met when they were writing for Da Ali G Show, where the two became fast friends. A few years later, when Reiser was diagnosed with cancer and given a 50/50 chance of survival, Rogen was by his side through the entire ordeal. And it truly seems to have become their ordeal, which became evident when I sat down with the pair to discuss 50/50, which is based on their experience. Joseph Gordon-Levitt stars as Adam, who gets diagnosed with cancer, and Seth Rogen plays Adam’s best friend.

Will and Seth finish each other’s sentences, and Will perpetually refers to his cancer as a joint journey. Going into this interview, I pretty much had one goal in mind: become friends with Seth Rogen. Spoiler alert: it didn’t happen. But I did get to chat with the duo about Reiser’s unconventional bout with cancer, the courting of Joseph Gordon-Levitt, and Rogen’s forthcoming screenplay about a group of friends who confront their issues during the apocalypse. Here’s what went down:

*SPOILERS AHEAD*

BYT: Will, Seth, great to meet you both.

Seth: Thanks for sitting with us

BYT: First off, I loved the movie. I can honestly say I haven’t heard a bad word about it.

Seth: It’s crazy. Don’t jinx that.

BYT: Will, this was based your experience. How closely did this follow how things actually went down?

Will: It’s less that the scenes actually depict things that happened. [The similarities] are more thematically. It draws upon what I experienced in various different relationships. Also, the way in which my friends and I used humor to cope, and how at that time in my life I was incredibly neurotic. Seth would describe me as annoying.

Seth: Used to be annoying.

Will: And how I wasn’t able to express myself or what I was feeling at the time.  [The character's] emotional arc is very much an extension of me and what I went through, but the actual things that happened aren’t exactly the same. Well, those are my MRI’s.

Seth: And we worked together.

Will: And he was my closest friend.

Seth: The question we were asking ourselves wasn’t, “Did this happen?” It was, “Would this happen?” We asked ourselves, “Does this feel real?” Like, in an earlier draft there was a scene with a rabbi. And I looked at Will and said, “Would you go talk to a fucking rabbi?” No. So, we took it out.

Will: I have not been back to synagogue since. My view of religion is still exactly same.

Seth: But we would let life guide us sometimes in that way. We couldn’t think of an ending, and we remembered that time when I changed the dressing on the wound. It was revolting.

Will: He’s very squeamish.

Seth: I am.

BYT: Can you talk about the casting? You had a really strong cast.

Will: Yeah, everyone we wanted we got. The only person who auditioned was Bryce [Dallas Howard, Will's girlfriend in the film]. We refused to just offer that role to anyone. It’s a really hard character to play. To be able to play that character and not just feel like a bitch–

Seth: — Or a cartoon character. We didn’t know if you’d necessarily sympathize with her but we wanted you to be able to intellectually understand that.

BYT: What about the parents?

Will: Angelica Houston was our first choice, and she wanted to do it. And Serge [Houde, Will's father] auditioned (he was a local hire). We filmed in Vancouver, and that’s where he’s from.

BYT: So, after you beat cancer, at what point are you like, I’m going to write a movie about this?

Will: When I was sick and Seth and I were going through the whole ordeal, we would talk about how our experience was so different. You know,  people’s impression of what cancer is is based on what they see in movies. So people would ask me all the same questions.

Seth: It’s always like My Life, the Michael Keaton movie. Or The Bucket List.

Will: The Bucket List was a huge one. People would always be like, “What’s [on] your bucket list?”

Seth: …To punch you in the face.

Will: We were at a party and someone asked me that question and Seth and I were like, “We should make a movie called The Fuck-It List.”

Seth: Where guys like do heroin and smoke crack and all the other fucked up shit you never get to do. They kill a guy.

Will: “I’ve always wanted to murder someone , and I have cancer. What do you want?”

BYT: You need to make that movie.

Seth: It’s not a bad idea for a movie…

Will: What we really felt was that there was no movie that portrayed what it was like for what we were going through.

Seth: More tonally than anything, not procedurally.

Will: Where you don’t just cry through the whole movie and they just die at the end. That’s what most cancer movies are. The person has this clarity and they understand life and who they are–

Seth. –And then they die.

Will: It wasn’t like that for me. It was dysfunctional and no one knew what to say and then I got better and you’re sort of left in the aftermath of that. And we just wanted to make something that felt totally honest. So after I got better, Seth and Evan Goldberg, who’s another good friend of mine and his writing partner, urged me to write the movie. As long as I knew that they were going to be my producers to support me, I felt much more comfortable opening up and writing about personal stuff. And they really pushed me because it’s hard to expose yourself.

BYT: Well, yeah, it’s tough. And especially with this material. It’s a real tearjerker.

Seth: I’m so aware where all the laughs are in the movie because I’m so not used to having a movie that bums people out. Like, whenever I’m watching it, I’m thinking there’s this thing this thing and then a laugh so don’t worry. We’ll get these people out of this.

Will: The one thing that without fail makes everybody laugh, the first huge laugh in the movie, is when Angelica Houston says, “I’m moving in with you.” And that’s the first thing my mom said. She got on a plane and flew to LA. And I immediately had to put her on a plane and send her back.

BYT: Can you guys talk about your writing processes? Like, what’s an afternoon of writing like for you two?

Seth: We write really differently. You really agonize.

Will: I write pretty slow, and spend a lot of time developing character. Not that you don’t… But I do a lot of research and that’s actually how I spend most of my time. I find that if I’m trying to force myself to write things that means I don’t have the character. Because usually if I know the characters really well, then I’ll dictate what they’re going to say.

Seth: [Evan and I] tend to start with more scene ideas and stuff we want to put in a movie. And we make a lot lists. Like, right now we’re writing this movie about the apocalypse. So we’re just writing lists of sort of apocalypse-y things. Sink-holes. Demons. Exorcisms.

Will: And I ask, “What is the demon confronting?”

Seth: Yeah, we don’t do that. We come up with lists and then funny ideas come out of it. Maybe someone gets possessed and there’s an exorcism? But we always go in knowing the basic outline. Like that movie, we know it’s about a group dynamic. It’s about a group of friends who have a bunch of issues and they’re forced to confront them by being trapped in a house together during the apocalypse. That’s the first idea we have, and then we try to fill in the blanks. But, actually, sometimes characters are the last thing to get developed. And we kind of have a general series of events we want and then we kind of fill in the relationships.

Will: I have to say, sometimes when you’re just actually writing it, that’s when you figure a lot of the stuff out as well.

BYT: What about the therapy scenes with Anna Kendrick? Were those tough to write?

Will: I did have to spend a lot of time working on those therapy scenes.

Seth: There was always the “good” therapy scene which turned into the scene where [Katherine, Kendrick's character] kind of confronts him about his mother and that was the hardest scene to write in almost the entire movie. It’s easy to write bad therapy scenes.

Will: We really needed to show her growth and we also needed to call Adam out on his behavior.

Seth: I remember that’s the [scene] we kept sending back to Will and saying that’s not what it needs to be.

Will: It would have worked in a more mediocre movie, but we wanted it to be really special. I finished that scene like an hour before we shot it.

Seth: I remember that.  It was crazy. I was not pleased.

Will: It has the one line I’m most proud of: “So your mother has a husband she can’t talk to and a son who won’t talk to her.” That whole storyline between him and Angelica totally came together in that moment.

Seth: A lot of moms got calls after that.

BYT: And what about Joseph Gordon-Levitt? I know James MaCavoy was your first choice for the lead role.

Will: We basically had one hour to figure it out. Seth and I were living together in Vancouver, and I remember we went home and I said, ”What about Joseph Gordon-Levitt?” And you called him.

Seth: I said, “This is not an ideal situation, but we have a movie that’s really good that starts filming in one week. And we need you to tell us tomorrow whether or not you want to be in it.”

Will: He read the script, got on a plane–

Seth: — Hung out with me, Evan, and [director] John Levine as we drank beers for around 8 hours on Levine’s roof.

Will: Until 5 in the morning.

Seth: Yeah, like really long. I remember thinking, “How long do we have to do this?” And he was feeling us out. It was like a forced attempt at what is generally an organic process, which is like the getting-to-know-you-feeling-each-other-out process that you generally have when you’re deciding whether or not you want to do a movie. So, usually that happens over the course of a few meetings and script meetings. Here, we really had to condense it into one night and he told us he would do it at the end of the night… He flew back to LA, got his stuff, and flew back to Vancouver the following Monday. Then we rehearsed that week and did wardrobe fittings and wig adjustments.

Will: By the way, it takes two weeks to make a wig and we had one week.

Seth: I think he’s wearing Cobra Commander’s wig in the movie. It’s incredibly courageous what he did as a performer because most people would want a lot of preparation for a role like this and would want to talk to a lot of people and absorb things. And we just threw him into it. Once he committed to it, he took complete ownership over it. It was as if he had been attached for months.

Will: And i didn’t try to impose anything on him.

Seth: Will was around, but we told him we didn’t want him to act like Will. We didn’t want to see a guy doing a Will impression. Just us as people who know Will, we didn’t want to see that.

Will: What’s interesting is people who know me really well still say it’s exactly like me. Or, exactly like who I was when I was 25. I’m more relaxed now.

Seth: But Joe would never ask Will about behavioral things, it was always emotional things. Like, he would never ask him how he held a cup, but he’d ask, “How did you feel when you had to tell your mother you had cancer? How did you feel when you went to therapy for the first time?”

Will: The thing about everyone on the film is that if we weren’t friends, we became friends. We were just at the Toronto Film Festival where we premiered the movie, and honestly, I feel like these are all members of my family. Bryce, Anna, Joe, Jonathan Levine. Seth and I have known each other for a long time and I just feel so comfortable with those guys. Everyone was so easy going, and it was such an easy movie to make. It was like a dream.

Seth: Yeah it was one of the easiest movies I’ve ever made.

BYT: Thank you both, and congratulations.

50/50 opens today. Our review is coming up ASAP.