For when you have run out of other options and are not above saying so. Three sentences, and they make an argument: nobody who ever came to her was turned away, so here I am.
It is the one prayer to Mary that reasons with her. Never was it known that anyone who came to you was left unaided — that is the premise. Inspired with this confidence, I fly unto thee — that is the conclusion. It is a syllogism you can say in a car.
And it admits two things at once, sinful and sorrowful, and asks for neither to be fixed. The request is smaller than that: despise not my petitions. It asks to be heard. That is why it has become the prayer people reach for when they have nothing else — it does not require you to be in good shape to say it.
You will be told St Bernard of Clairvaux wrote it, and the prayer is called his in a thousand prayer books. The words are not his; they are an extract from a longer fifteenth-century Latin prayer, three hundred years after his death, and no manuscript puts his name on them.
What is documented is how it spread, and it explains the mistake. In the 1630s a Paris priest named Claude Bernard — known as the Poor Priest for his work among the condemned and the destitute — credited this prayer with his recovery from a mortal illness, and had it printed by the hundreds of thousands to give away. A prayer promoted everywhere by a man called Bernard, with a famous Bernard in the calendar, got attached to the wrong one. That is the likeliest story, and it is a better one than the legend.
It became the emergency prayer. There is a novena of nine Memorares, and Mother Teresa's sisters describe her flying novena — nine Memorares said in a row, on the spot, when there was no time for nine days, and then a tenth in thanksgiving before the answer came. That is a woman who had read the prayer's own logic and taken it at its word.
It is short enough to be in the pocket, and long enough to be a whole prayer. Most people who know it learned it from someone who needed it once.