From Too Much Happiness by Alice Munro:
Weierstrass had no more idea than his sisters of Sophia’s age or mission. He told her afterwards that he had thought her some misguided governess who wanted to use his name, claiming mathematics among her credentials. He was thinking that he must scold the maid, and his sisters, for letting her break in on him. But he was a courteous and kindly man, so instead of sending her away at once, he explained that he took only advances students, with recognized degrees, and that he had at the moment as many of those as he could handle. Then, as she remained standing — and trembling — in front of him, with that ridiculous hat shading her face and her hands clutching her shawl, he remembered the method, or trick, he had used once or twice before, to discourage an inadequate student.
“What I am able to do in your case,” he said, “is to set you a series of problems, and ask you to solve them and bring them back to me one week from today. If they are done to my satisfaction, we will talk again.”
A week from that day he had forgotten all about her. He had expected, of course, never to see her again. When she came into his study he did not recognize her, perhaps because she had cast off the cloak that had disguised her slender figure. She must have felt bolder, or perhaps the weather had changed. He had not remembered the hat — his sisters had — but he had not much of an eye for female accessories. But when she pulled the papers out of her bag and set them down on his desk, he remembered, and sighed, and put on his spectacles.
Great was his surprise — he told her this too at a later time — to see that every one of the problems had been solved, and sometimes in an entirely original way. But he suspected her still, thinking now that she must be presenting the work of someone else, perhaps a brother or lover who was in hiding for political reasons.
“Sit down,” he said. “And now explain to me each of these solutions, every step taken.”
She began to talk, leaning forward, and the floppy hat fell over her eyes, so she pulled it off and let it lie on the floor. Her curls were revealed, her bright eyes, her youth, and her shivering excitement.
“Yes,” he said. “Yes. Yes. Yes.” He spoke with ponderous consideration, hiding as well as he could his astonishment, especially at the solutions whose method diverged most brilliantly from his own.
She was a shock to him in many ways. She was so slight and young and eager. He felt that he must soothe her, hold her carefully, let her learn how to manage the fireworks in her own brain.
All his life — he had difficulty saying this, as he admitted, being always wary of too much enthusiasm — all his life he had been waiting for such a student to come into this room. A student who would challenge him completely, who was not only capable of following the strivings of his own mind but perhaps of flying beyond them.