Lainey coined a term, “Hollywood Sliding Doors”, to describe the what-ifs of casting. Like that Gwyneth Paltrow movie Sliding Doors, in which dual realities play out—in one plot Gwyneth got on the Tube in time to get home and catch her boyfriend cheating. In the other plot, she just misses the train and continues on with her worthless partner (it’s a good movie from Gwyneth’s glory days). Hollywood Sliding Doors is about imagining what a movie would be like if the casting played out differently. The truth is most projects pass through several hands before getting made. You hear stories of actors sticking with something for years—current example is Brad Pitt and Moneyball—but usually casting is an ongoing process until production begins. Actors outgrow roles, they get pregnant or have to go to rehab, they commit to multiple projects and end up having to choose between them—the reasons for Hollywood Sliding Doors are myriad.

50/50 is a great example of Hollywood Sliding Doors. Originally known around town as “Seth Rogen’s cancer comedy”, 50/50 is based on the real-life story of Will Reiser (who wrote the script and worked on Da Ali G Show with Rogen), who was diagnosed with a rare form of cancer in his twenties. “Adam”, his proxy in the movie, was originally to be played by James McAvoy. Unfortunately, McAvoy had his own real-life situation (it’s sad and we won’t talk about it) and he had to withdraw from the project. The role ended up going to Joseph Gordon-Levitt. We’ll never know what would have been had McAvoy remained in the role, but I do know that what Gordon-Levitt did, only he could do. The balance of light and dark in Adam is a very fine line and Gordon-Levitt navigates it so easily and with such goodwill and humor that I can’t imagine anyone else even coming close. Not even another good actor like McAvoy.

Heed my warning—bring tissues. I didn’t and ended up bumming some off T. I was a sobbing mess. It starts early in this movie and it’s unrelenting throughout. You will cry. And not just tears of sadness! Tears of joy, and friendship, and love. You will cry all the tears. And you will laugh! You will laugh and it’s fun and it’s true and you know these people and these feelings, if not the exact situation. And then you will laugh and it’s pain, because there’s nothing else to do. Laugh or give up and you can’t give up! You must laugh. You will laugh all the laughter. It’s a huge testament to Reiser’s script and Jonathan Levine’s (The Wackness) direction and the cast’s acting that 50/50 never, not once, feels emotionally manipulative. This movie runs on pure, honest emotion and the things it makes you feel are real things. You will feel good when this movie is over. You will feel alive.

The story opens with Adam jogging through Seattle. In one shot we learn he is a rule follower—while Adam jogs in place at a red light, even though there are no cars around, a fellow jogger goes through the intersection. Adams continues jogging in place, obeying the traffic lights (I get this scene and what it’s establishing about Adam, but if you’re at all familiar with Seattle you know the jaywalking fines are hundreds of dollars and NO ONE jaywalks in Seattle, except tourists). We catch up with Adam in line for coffee with his friend Kyle (Rogen). Adam has back pain. He’s going to the doctor. The pain turns out to be a rare cancerous tumor on his spine. His odds are 50/50.

Adam is understandably baffled. He’s a health nut, he’s young (only 27), but more importantly, he’s a nice guy. Cancer isn’t supposed to happen to nice young men. Kyle’s reaction is simultaneously funny and crushing. “I’m going to throw up,” he says, and you believe it. The scenes of Adam informing his friends and family of his new status as cancer patient are a perfect example of how 50/50 combines humor and sadness. Kyle compares Adam to a casino game, trying to make light of his odds. Adam’s mother (Anjelica Huston, doing a pleasingly nutty turn as an overbearing mother) wants to move in and take care of her baby. Adam’s girlfriend Rachael (Bryce Dallas Howard, The Help)—well, it’s clear how that’s going to go from the beginning.

If I have any problem with 50/50 it lies in the sometimes too-pat nature of the script. We know immediately what will happen with Adam’s cold girlfriend and his cute, young therapist (Anna Kendrick, Scott Pilgrim vs. the World). From the moment Adam makes friends with the older patients in his chemo group, we know one of them will die. The relationships tend to travel paths that are a little too well-worn. However, Reiser’s story also evinces touches of real grace. For instance, after confronting Kyle for being a shitty friend, more concerned with getting laid or high than anything else, Adam finds a copy of Facing Cancer Together in Kyle’s apartment. With Kyle passed-out drunk in the background, Adam flips through the book and we see heavy underlining, dog-eared pages, and marked passages like “don’t get emotional” and “focus on the positive” and “maintain a routine together”.

But the true strength of 50/50 is all on Gordon-Levitt. Rogen does what he does, and he does it well, and Kendrick acquits herself nicely, but the movie lives and dies on Gordon-Levitt. He is more than up to the task. There’s one scene of such raw emotional display that it’s almost terrifying. If he does get nominated for anything—and he will at the very least be part of the conversation—that scene is his “Oscar moment”.

50/50 is a rare movie—one that is honest. It’s a truly moving story that, despite a tendency toward the facile, never relies on tricks to make us feel something. Instead it gives us a flawless cast turning in superb work from a strong script and excellent direction, all working together seamlessly. This is a together movie. What you feel in that theater, everyone in that theater feels, too. You do it together, a temporary support network witnessing something touching and funny and profound. You don’t go through it alone. Thinking back to that book in Kyle’s apartment, that’s kind of the point.