How Rosie O'Donnell's Mother's Death at a Young Age Shaped the Star's 'Astounding' Path in Life

Gene Reed

Rosie O'Donnell never dreamed she'd lead such an "astounding" life — especially after unthinkable tragic struck her family when she was only 10 years old.

"I never imagined being 60," the entertainer, who turned 61 on Tuesday, exclusively tells PEOPLE. "My mother died at 39. She died on St. Patrick's Day, 50 years ago, and it feels like it's yesterday. It feels like, How could that be 50 years ago?"

Even though O'Donnell once associated St. Patrick's Day with celebration due to her Irish heritage, she said it's "always a hard day" since her mother's death.

"Everybody is like, 'Hey, Rosie, it's our day, man.' I always think, Yeah, kind of, it's our day. But I remember being 10 years old and going in the bathroom and looking in the mirror and saying, 'Nothing bad can happen today because it's good luck for the Irish.' And then the worst thing happened that day," she recalled.

She recalls of that life-changing day: "I was over at [my friend] Jackie's, and somebody from my house called and said, 'Roseanne has to go home.' And then Jackie's mom — who's still with us — pulled the phone all the way to the other room so she wouldn't have to look at me because she was crying. She said, 'Roseanne, go home.' And I was like, 'What happened?' I went home and there were 20 cars on the street. I'm like, 'What's going on?'"

She continues, "My father was a mess. And all of his siblings were there, and everybody was a mess. They said, 'Your mother passed away.' And I remember thinking, What does that mean, 'passed away'?"

"We didn't have the right vocabulary," she says. "It was not in the time of Oprah Winfrey and grieving children and [open discussing of] 'How do you survive the death of a parent?' All those things were to come later in life. But right when it happened, in 1973, it was pretty much earth-shattering."

O'Donnell has come to consider her mother's passing a "really defining moment."

"Here I am now, a grown woman in the last chunk of my life," she shares. "That gives you a different perspective. Because my mother died so young, I didn't ever have that, Oh, I am afraid to get old. I felt every year after 40 was a gift."

She adds, "And now, here I am having lived 21 years more, or 22 years more than she did. It's pretty astounding to me."

RELATED: Rosie O'Donnell Is Moving Onward at 61 with a 'Third Chapter' of Her Life — and a New Podcast

O'Donnell's storied life and career over the last five decades has seen her host The Rosie O'Donnell Show and The View while penning multiple books and appearing in several films and TV series.

And on the same day she marked her 61st birthday, she also launched her new podcast Onward, with Sharon Gless, Jenifer Lewis, Camryn Manheim, Ricki Lake, Kathy Griffin, Dylan Mulvaney and Rory Kennedy among the guests she'll welcome in coming weeks.

Gene Reed/iHeart Media

RELATED: Rosie O'Donnell Says She's Been Asked to Bring Back Her Talk Show: 'You Never Know'

With each episode, O'Donnell aims to have an "intimate conversation ... talking about topics that inspire or that I'm curious about, or that I am drawn to in some way — and hopefully people will respond."

She explains, "When I turned 60, I felt as though life is like a three-chapter book: 0 to 30, 30 to 60, 60 onward."

Now, she adds, "I'm in the third chapter of the book. So let's put all the past in the past, and let's just focus on being where we are right now, and onward to another day. That's kind of the place that I'm at in my life and career. That's the place that we arrive at the podcast."

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The first episode of O'Donnell's Onward podcast is now available to stream on all major podcast platforms.