Occlumency

'Harry there is nothing so important as you learning Occlumency!' said Lupin sternly.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

With a surge of guilt he realised that he had not practised Occlumency once since their last lesson: there had been too much going on since Dumbledore had left; he was sure he would not have been able to empty his mind even if he had tried.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

He had the horrible impression that he was slowly turning into a kind of aerial that was tuned in to tiny fluctuations in Voldemort's mood, and he was sure he could date this increased sensitivity firmly from his first Occlumency lesson with Snape.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

'Dumbledore doesn't want you to have dreams about that corridor at all, or he wouldn't have asked Snape to teach you Occlumency.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

After a few minutes, however, he remembered that he was supposed to be emptying his mind of all emotion before he slept, as Snape kept instructing him at the end of every Occlumency lesson.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

Only those skilled at Occlumency are able to shut down those feelings and memories that contradict the lie, and so can utter falsehoods in his presence without detection. '

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

Harry would have given a great deal to be making as much progress at Occlumency as Neville was making during the DA meetings.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

'You must study Occlumency as hard as you can, do you understand me?

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

'The Headmaster has asked me to teach you Occlumency.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003

He could not help feeling that his first foray into Occlumency had weakened his mind's resistance rather than strengthening it, and he wondered, with a feeling of great trepidation, what had happened to make Lord Voldemort the happiest he had been in fourteen years.

Harry Potter and the Order of the Phoenix Rowling, J. K. 2003