Jews did not speak with Samaritans, and men did not speak with unknown women at wells. Jesus asked her for a drink. The conversation moved from water to thirst to the five husbands she had had and the man she now lived with. He said it plainly and without contempt, and she did not run.
She left her jar and went into the town she had been avoiding, telling people to come and see a man who had told her everything she ever did. Being fully known and not rejected became the thing she could not keep to herself. The Church reads this scene to those preparing for Baptism, because it is what living water does.
Whoever drinks of the water that I shall give him will never thirst; the water that I shall give him will become in him a spring of water welling up to eternal life.
John 4:14, RSV-CE