At the same time, Mr. Eustis, who attends theater five or six nights a week, finds himself newly angered by shows that he believes present an overly rosy picture of life — particularly on Broadway, where the triumph over tragedy is a staple. He is infuriated, he says, by “narratives that imply that children are always reunited with their parents, that dead people aren’t really dead.”

“What I see over and over is narratives that are absolutely lying to the audience about how life works out, and they are lying to the audience for the sole purpose of making the audience feel good,” he said. “That’s not what art is for.”

“The mission that I feel like I have is to figure out how you can tell the truth about how tragic and unfair life actually is without destroying hope,” he added.

As the two-year anniversary of his son’s death approaches, and a new season at the Public gets underway, Mr. Eustis is seeking hope himself. He is thrilled with the success of “Twelfth Night,” this year’s Public Works endeavor; pleased with the audience appetite for Mr. Nelson’s Gabriels plays; and looking forward to a revival of “Plenty,” which opens Oct. 20.

One sign of change: This past spring, when “Dear Evan Hansen,” a heart-wrenching musical imagining the aftermath of a high school student’s suicide, was playing Off Broadway at Second Stage, the show’s director, Michael Greif, persuaded the Eustises not to come, thinking elements of the show would just be too painful.

Now the show is heading to Broadway, and, at the moment, the Eustises are planning to be there opening night.

Mr. Eustis said that he has also recently noticed a change in his own behavior: He has found himself straightening up and organizing his office and home.