Harrison Ford said, "This mixture of comedy and pathos and really emotional stuff, it gives you a sense of responsibility for the things you're communicating and how you're communicating. I think that that shows up on screen, and it shows up in the work these people do every day and how they do it. I had never done anything like this before and it was like suddenly recognizing what I've always wanted [acting] to be." He told Apple CEO Tim Cook "about the experience that I have with people who come up to me and say something about the show. And then I get to say something... and then they turn around and walk away. They do not want a picture. They do not want an autograph. They do not want to do anything. They just want to communicate that this means something to them. And it's an extraordinary experience in my life. That is a real thing. And it means the world to me."
When Brett Goldstein, Jason Segel, and Bill Lawrence were asked how they got Harrison Ford to be in the show, Segel said that Goldstein originally wanted a "Harrison Ford type," and was going to audition people similar to Ford. Segel told Goldstein they had to at least bring it to Ford first, thinking he would turn it down immediately, but at least other people would hear that Harrison Ford was brought the project, generating interest from other notable actors. In the end, Goldstein talked to Ford and sold him on the role. Goldstein still doesn't understand what he did to convince him, but was elated nonetheless.
When Harrison Ford was approached for the series, the producers told him to watch Nie wieder Sex mit der Ex (2008) to familiarize himself with Jason Segel's work. After seeing it, Ford texted Bill Lawrence saying, "I'm in. BTW, good dick," referring to Segel's nude scene in the movie.
The character of Paul (Harrison Ford) was based on therapist, Phil Stutz, who was the subject of Jonah Hill's Netflix documentary Stutz (2022).