The world knew Adrienne Rich, who died last week at 82, as a poet - influential, political, feminist, lesbian, anti-war, Jewish.

But her profound impact on my life came in the form of prose: a 1976 book called "Of Woman Born: Motherhood as Experience and Institution." Rich, who was a wife until her 40s and the mother of three boys, trained her rebel's eye on the mixed feelings that come with caring for babies and young children.

To be sure, Rich had her predecessors on this ground: Betty Friedan, even the humorist Erma Bombeck. And Rich inspired thousands who came after, from Susan Maushart, who wrote "The Mask of Motherhood," to the many parent-lit moms and dads writing and blogging today.

It's not that parenthood is awful, of course. It's that mothers were to an excessive degree expected to be "beneficent, sacred, pure, asexual and nourishing," as Rich described it, or they would risk disapproval. Rich was instrumental in shattering these public myths that made women feel privately inadequate and unnatural if they discovered any forbidden feelings in the nursery.

More important, this long march away from the perfect angel mother toward a more nuanced - if darker - portrait of parenting paved the way for recognition of postpartum depression so that women and their families could get help. Even the impossibly perfect Brooke Shields published an account, in 2005, of her postpartum depression, "Down Came the Rain."

Rich wrote looking back. She was 46 when "Of Woman Born" was published, and her eldest son was 21. "I only knew that I had lived through something which was considered central to the lives of women, fulfilling even in its sorrows, a key to the meaning of life; and that I could remember little except anxiety, physical weariness, anger, self-blame, boredom, and division within myself: a division made more acute by the moments of passionate love, delight in my children's spirited bodies and minds, amazement at how they went on loving me in spite of my failures to love them wholly and selflessly."

She included journal entries from her days with babies; at one time her three sons were all younger than 7. The entries are startlingly candid: "Degradation of anger. Anger at a child. How shall I learn to absorb the violence and make explicit only the caring?"

"Of Woman Born" is sometimes overlooked amid Rich's 30 books of poetry and prose published over six decades. Its radical take on women's domination in a patriarchy is and was controversial. But the beautifully rendered descriptions of the inner life of this one mother, a poet, is what makes the book so reassuring to parents who can relate to the loss of independent identity and the isolation that comes with caring for a child.

What parent taking a phone call wouldn't recognize this passage? "As soon as [my son] felt me gliding into a world which did not include him, he would come to pull at my hand, ask for help. ... And I would feel [it] ... as an attempt moreover to defraud me of living even for fifteen minutes as myself."

Rich was born in Baltimore, and her father, a pathologist, encouraged her to read poetry from childhood. Her mother was a concert pianist. After graduating from Radcliffe College in 1951, Rich published her first book and soon after, married Alfred Conrad, a Harvard University professor.

They moved to New York in 1966. Four years later, Rich left her marriage, and within several months, Conrad took his own life. It's tempting to see the negative aspect of her writing as a product of this unhappy biography.

But most parents will recognize Rich's ambivalence as truth-telling.

Essay first published in Newsday.