Archbishop Diarmuid Martin choked up on national radio as he described a mother's first meeting with the grown child she had given up for adoption.
The Catholic primate (75) called for greater openness and enhanced tracing of birth parents and children, in an apparent commentary on last week's Mother and Baby Homes controversy.
Appearing with Miriam O'Callaghan on RTÉ Radio 1 to mark his impending retirement, Dr Martin related that when he was a younger man, "this boy came out of an industrial school and asked me: 'Would you be able to find my mother?'
"And we did find the mother. And we went to a Mother and Baby Home, and I remember the nun said: 'That woman had no interest in her child,' but we kept going.
"One day we arrived into the snug of a pub in a rural town and asked to see this woman.
"And in she came. She was elderly and she was terrified.
"She was cleaning the place, and she had a black beret in her hand, which she kept fingering.
"And we said to her, 'Do you ever remember a little boy?'
"And her face lit up," said Archbishop Martin, his voice trembling with emotion. "And you could see on her face, 'He's alive. Somebody knows him, somebody's looking after him.'"
Struggling with his breathing, the Archbishop went on: "It sticks in my mind, that woman.
"Now, it didn't work out - neither he nor she really had the ability to bond. But it wasn't that she wasn't interested in her baby; that baby was there all the time."
Miriam O'Callaghan told him: "I can see how moved you are by all of that."
Archbishop Martin said: "That's many years ago. I don't know that many people wanted to give up their baby, but because of the circumstances they were in, some may feel now they were forced to give up their baby."
The Murphy Commission report on Mother and Baby Homes, which the Government has said it will publish as soon as possible, would "verify some of these things", he said.
"But that expression on that lady's face will stay with me."
"It happened when there was a harshness in Irish society and a harshness in the Irish church, he said.
Pope Francis, when meeting with the Irish hierarchy, had warned them to keep away from the "harsh judgmental church, which had done so much damage in the past".