Forget what F. Scott Fitzgerald said about no second acts in American lives. Playwright Israel Horovitz is proof enough that it’s not true. Horovitz, who turned 75 in March, will be at the Gloucester Stage Company Monday for a staged reading of his latest play, “Gloucester Blue,” and then it’s off to LA and New York to hype “My Old Lady,” a feature film — the first he’s directed — based on his own play. And then there’s a book of poetry, which will come out just as the movie is opening. In the meantime, Horovitz was at Gloucester Stage Company Friday to talk to the aspiring writers enrolled in the Youth Acting Workshop. “I was not to the manor born,” says Horovitz, who grew up on the same Wakefield Street as writer Russell Banks. “Russell and I dreamt a life and then we tried to live it. That’s what you have to do. Frank McCourt once said, ‘My life saved my life,’ and we subscribe to that. We wrote about life and, by God, it gave us a life.” Horovitz’s new play, “Gloucester Blue,” which he hopes to eventually take to New York, is a dark adult comedy about house painters, sex, violence, and murder. (The readng will feature Therese Plaehn, Francisco Solorzano, Lewis Wheeler, and Robert Walsh.) The movie, starring Maggie Smith, Kevin Kline, and Kristen Scott Thomas, will debut Sept. 7 at the Toronto International Film Festival.