That was a harder time. The thing about staying in the same hotel suite for all these years is that it remains a museum of the things you’ve left behind. He drank a lot. He suffered a lot. His history here, he said, “was really severe.” He remembers waking up in the bathtub. He remembers waking up in a bowl of macaroni and cheese. He remembers trying to have pot delivered. “I just created a lot of havoc. I didn’t give a [expletive], man.”

His mother, a Texan named Jane Cameron Agee, was “really severe,” too, he said. She was a casting director and an animal activist who, 12 days into knowing James Brolin, drinking Scorpions, said something Texan like, “So, are we going to get married or what?” She didn’t have a lot of patience. When he was little, Josh wrote a poem about death in the shape of a circle. He showed it to her, and she said, “What is this?” His father used to say that if his mother was trying to teach one of her kids how to read, and they didn’t get it immediately, well, you had five minutes and then she was done with you. She once told Josh that there was something in her that needed to create obstacles and misery where there didn’t need to be. “Which was very me,” he said. “If there was no obstacle, I would create it. I had to have an obstacle to feel like I existed.”

He said she had “a very Sam Shepard kind of existence.” Once, she was dating a guy Josh’s age; apparently, the boyfriend threatened to leave, and she pointed a .22 rifle at him, which was a regular event, according to Mr. Brolin. He left anyway, and his mom chased him down the road in her car; afterward, she called her son to say she’d hit an embankment at 90 miles an hour and had broken her back.

But that’s not what killed her. She died years later, driving fast again. This time it was a tree she hit. But this time, she didn’t call Mr. Brolin. Instead, a friend of the family, a radiologist, called to tell him that she was in the hospital and that there was no brain activity. From his apartment he told them to pull the plug. He didn’t wait to see her one more time. He knew she was gone for good. “That’s all romantic [expletive].”

Mr. Brolin said he confined his drinking to binges, away from home where his kids couldn’t see. He was settling down after a childhood that included drugs, drinking, participation in a punk band, an intentional frost-tipped mohawk, theft, arrests, at least one stint in juvie and emancipation from his parents at 16.

Despite all this, he said, he was known in his family as the responsible one. “I loved it. I loved being a dad, and I loved being responsible, and I was the guy that everybody in the family came to and it was like, well, if you need to put something together, if you need somebody responsible, it was always me. Until it wasn’t.”