In the sheltered community of Isaac Mizrahi’s childhood, families competed for bragging rights as the wealthiest and most pious. A boy’s life revolved around religious study and girls were brought up to marry well. As for homosexuality, the very idea was simply beyond the realm of reality.

“I stuck out like a chubby gay thumb,” Mizrahi writes in his memoir “I.M.” The Brooklyn boy preferred Barbies to G.I. Joe, belted out diva impersonations and spent hours creating elaborate puppetry in his basement. He found his escape valve as a teen at none other than the Manhattan performing arts high school depicted in the movie “Fame.” There, Mizrahi spent his freshman year adjusting to culture shock and guilt. But once that was out of the way, he found his way in disco-era Manhattan, landing a job with designer Perry Ellis during his junior year and striking out with his own renegade fashion house by his mid-twenties.

“It was not a happy childhood, but I don’t regret that,” says Mizrahi, 57, who appears this month at the Katz JCC Festival of Arts, Books and Culture. “The idea of learned optimism is a theme throughout the book. As a teen, I was exposed to the idea that happiness could exist. The world wasn’t such a horrible, scary place and I could go into it.”

In spite of lifelong struggles with body image, self-doubt, depression and insomnia, Mizrahi has always moved forward. He burst on the New York fashion scene in the 1980s, dressing and designing clothes for A-list celebrities, including his idols Barbra Streisand, Liza Minnelli and Audrey Hepburn. A trailblazer who popularized the mash-up of high-and-low fashion, Mizrahi’s styles have also made their way into the wardrobes of budget-conscious fashionistas – thanks to successful collaborations with Target and, more recently, QVC. He has hosted a talk show, regularly performs cabaret (an early version was titled “Les MIZrahi), judges on “Project Runway” and was the subject of “Unzipped,” a documentary of his 1994 fall show that revealed behind-the-scenes glimpses of the world of high fashion in the age before Instagram. Also, he’s a creative cook whose website is chock full of his recipes.

Through every stage of reinvention, Mizrahi has been known for being bold, witty, warm and fun. Although he’s made peace with being best known as a clothes designer, he sees himself foremost as an entertainer.

“I’ve always thought of myself as in show business, even when I was a designer,” he says. “When I was tied to a design company, I had to produce four to six fashion shows a year, which was great fun until it wasn’t anymore.

Now the thrust of my energy is in creating and promoting myself as an entertainer. It’s exciting not to be doing the same thing I’ve been doing for a million years.”

As he writes in I.M., entertainment was truly his first love. But design was in the genes, and his genius for dressing women was a means of escape . His father, a manufacturer of children’s clothes, gave his son his first professional scissors on his Bar Mitzvah. His mother Sarah was a fashion original. Although never able to fully embrace his budding homosexuality, she bought her only son his first Barbie and regularly took him with her clothes shopping, feeding into his obsession with women and fashion.

Most memorable were trips to Loehmann’s, an iconic discount women’s clothing store. “It was this big, communal dressing room, and people grabbed each other’s clothes and it was quite competitive,” he writes. “I noticed some pretty strong psychological ties between women’s underclothes, and their clothes and who they were.”

Although he started studying drama in high school, Mizrahi pivoted from performance to fashion when he had the chance to design a dress for Diane Lane, then a 12-year-old up-and-coming actress. This led to a small business, financed by a friend of the family, college studies in fashion design and plum apprenticeships with Perry Ellis and Calvin Klein.

Of the many famous people he dressed, few made him starstruck like meeting Streisand, who he revered as a child. The two met when Streisand tried on his clothes at a friend’s apartment, he recalls.

“It was insane,” he says. “She was literally trying on my clothes, and I was pinching myself.”

Another thrill was working with Meryl Streep. An email the actress wrote him is permanently in his saved folder.

“Is it possible to bronze an email,” he says.

Such stories may come up when he visits the Katz JCC. That’s all up to the audience.

Mizrahi says his Q&As are often peppered with questions about shopping at Loehmann’s and growing up gay in a repressive community. Both are subjects dear to his heart.

“One of the reasons that I wrote the book was to reach out,” he says. “I worry so much about kids who aren’t exposed to such wonderful things that helped me get through adolescence. I want to send the message that it just gets better.”

Isaac Mizrahi will appear at the Katz JCC Festival of Arts, Books and Culture on Nov. 10. For more information, visit the website.