Why Wouldn't Jen Garner Play Ben Affleck's Wife?

Ben Affleck asked Jen Garner to play his wife, and she told him she was not going to do it. He thinks she is a great actress, and he wanted to see another side of her because he knows her so well. He says she is, as usual, a little wiser than he is.

Matt Damon had just gotten the Odyssey, and Ben Affleck says Damon was as happy as Affleck had ever seen him the day he got the job. Affleck knew it meant a lot. Damon had already had the opportunity to do lots of work, and the Odyssey was clearly meaningful. Affleck was really happy for him. He calls the experience great, and he thinks it would have been great even absent the result. Affleck decided to play the part himself rather than risk somebody else going off in another direction. Garner was the person he hoped would play the wife, for the same reason he likes working with Matt Damon, his brother, and people he has known a long time: you can steer them toward another side. He talked to her. She said she was not going to play his wife. He understood.