“How would it be,” she asked them coldly as they left the classroom for break (Binns drifting away through the blackboard), “if I refused to lend you my notes this year?”
“We’d fail our O.W.L.s,” said Ron. “If you want that on your conscience, Hermione. . . .”
“Well, you’d deserve it,” she snapped. “You don’t even try to listen to him, do you?”
“We do try,” said Ron. “We just haven’t got your brains or your memory or your concentration — you’re just cleverer than we are — is it nice to rub it in?”
“Oh, don’t give me that rubbish,” said Hermione, but she looked slightly mollified as she led the way out into the damp courtyard.

Harry Potter and the Order of the Phoenix – J.K. Rowling