When she was 17 years old, Mary Johnson saw a photograph of Mother Teresa in a magazine and knew she had found her future. Within two years, she had become a nun with the Missionaries of Charity, the order that Mother Teresa founded.
But 20 years later she left, torn by a desire for greater freedom than that offered by a life where writing poetry was discouraged in favour of writing daily notes to help remember her sins, physical touch was frowned on and members were not allowed to stay in close contact with their families.
"I was still very young, Mother Teresa was a person I admired very much ... I felt that she could show me who God was and how to please God, how to live well and how to love well," Johnson said in a telephone interview.
"So I tried to do it in the way that she had done it, which might have worked for her. But after a really long time, I discovered that it did not work for me."
Johnson chronicles her journey from earnest novice to struggling sister, and then beyond, in "An Unquenchable Thirst: Following Mother Teresa in Search of Love, Service and an Authentic Life."
The book details her efforts to obey, her early satisfaction in working with the poor in the Bronx, sometimes complicated relationships with her fellow sisters, and the loneliness that drives her to break her vows of chastity, once with a priest.
Johnson also writes of her experiences working with Mother Teresa herself, whom she portrays -- despite her affection for her -- as a woman sometimes overwhelmed by the mushrooming demands on her by both the world and the order she founded.
Some of these human descriptions of a woman who is already revered as a saint by many and has been beatified by the Catholic church have drawn criticism, but Johnson feels her portrayal is warranted.
"When there's an image projected of absolute perfection, I think it really doesn't serve anybody -- neither the people who are thinking that they have to achieve this as well, or the sisters. It's really dangerous," she said.
"If you think there's this perfect person that you're called to imitate and you have to live exactly like that ... even this person didn't achieve this image that you have. You're placing demands that are impossible to meet, and being frustrated all the time."
While Johnson says she gained much during her time as a nun, including working with what she terms many "extraordinary people," she says there were also many things that she lost, including 20 years of culture and history in the outside world.
"I'd never used an ATM before, I'd never used a microwave --
to say nothing of a computer. I didn't know any of the latest books, music, movies, and I still have a big gap there."
Despite criticism in some quarters, the book has, according to an article, prompted some comments from within the Missionaries of Charity that introspection may be needed, Johnson said, adding that she emerged from the convent still with much affection for Mother Teresa and the sisters.
But she also feels strongly that surrendering autonomy to a spiritual leader should be avoided.
"The most precious thing we have is our ability to be ourselves, I think, and to come to know who we are and to grow out of the center of our being," she said.
"We spend all our lives finding out who we are, and then for someone else to claim to know what's best for us -- I think that's really kind of impossible."