Leaning in isn’t something you do just once, and then congratulate yourself for accomplishing it. It’s more like a muscle you have to keep exercising. The stronger that muscle gets, the better you’ll become at fulfilling your task and reaching your dream.

I was a struggling young actress, looking for that first big break and trying to make a name for myself, when I heard that producers were casting to replace Elizabeth Ashley in the Broadway hit Barefoot in the Park. I jumped at the chance. I knew that the role of Corrie was perfect for me ­– vivacious, optimistic and funny. This was meant to be, I thought.

But when I got to the theatre to audition, my heart sank. There was a long line of young actors ­– male and female ­– waiting outside to audition. A few of them said it was hopeless and left. But I thought, “Well, someone has to get the part.” So I leaned in and waited in line, a little nobody among hundreds of nobodies. After a very long day I finally got to read for the director, Mike Nichols, who by then was already a huge success, and Neil Simon, who was on his way to becoming Broadway’s favorite playwright.

After my reading, Nichols gave me a direction (always a good sign) and asked me to try it again. The next day I got a call to come back. And after reading for them just one more time, I was told I had the part.

I was beyond thrilled – that is, until I found out that I hadn’t been reading for the Broadway replacement after all, but instead, the year-long national touring company.

I turned the offer down. My agent was furious and asked me why.

I explained that I had been trying to make my own way as an actress, but that whenever I appeared in anything, the interviewers and critics always compared me to my famous father, Danny Thomas. “I cannot travel this country for a year being compared to my father,” I told my agent. “I’ll go crazy giving interview after interview, in city after city, not about my work, but how it feels to be Danny Thomas’s kid. It will kill my spirit.”

My agent threatened me, saying I would never again be taken seriously after turning down such a break, but I stuck to my guns. I knew it was wrong for me.

Months later, I read that Barefoot was casting again, this time for the London company. I instantly knew that this was an ideal scenario for me: to get out of the country, go where my father wasn’t so well known, and stand or fall on my own. I desperately wanted to audition, but I knew I’d lost my agent’s support after the first go-round, so I decided to go straight to the source. Pacing in front of a phone booth in Greenwich Village, I took a deep breath and called Mike Nichols. I was sure he wouldn’t take the call – but I was wrong. He picked up and I launched into my pitch, asking him if he remembered me.

“I do,” he said warmly.

"Is there a chance I could read for the part of Corrie for the London company?” I nervously asked.

Silence.

“What a good idea,” he said finally, with what even sounded like a smile.

I don’t know if it was the sweat from my hands or the tears from my eyes, but I actually dropped the phone. I eventually got the part and went off to London, where the show received spectacular reviews – but none more liberating to me than the one in which a critic commented, “Marlo Thomas is the daughter of an American comedian, I’m told.”

The lesson I learned was invaluable: Leaning in isn’t something you do just once, and then congratulate yourself for accomplishing it. It’s more like a muscle you have to keep exercising. You need to lean in every day. The stronger that muscle gets, the better you’ll become at fulfilling your task and reaching your dream.