But nobody ever knew what Mary Poppins felt about it, for Mary Poppins never told anybody anything. - P. L. Travers

Mary Poppins never told anybody anything. . . .

The lambs in their arms were as smooth as mushrooms, the flock at their heels unruffled. And amid all that froth of fleece, white and metrical as soap-suds, there was no sign of a black lamb.
What more could one ask, at a children’s Christmas Eve service? Yet I found that I did indeed want more, especially for the children’s sake — faces trodden by crows’-feet, signs of the ferment, one might almost say chaos, that this unprecedented event brought once and ever brings; something of life, even in carven faces, someone out of breath with running, someone stricken with joy.
And I dearly wanted a black lamb. For, without him, where are the ninety and nine? Flocks, like families, have need of their black sheep — he carries their sorrow for them. He is the other side of their whiteness. Does nobody understand, I wondered, that a crib without a black lamb is an incomplete statement?

very quiet and still, as though it were thinking its own thoughts, or dreaming perhaps.

Nothing I had written before Mary Poppins had anything to do with children and I have always assumed, when I thought about it at all, that she had come out of the same well of nothingness (and by nothingness, I mean no-thing-ness)