It was bad enough that he kept revisiting the graveyard in his nightmares, without dwelling on it in his waking moments too.
The Dark Lord is at a considerable distance and the walls and grounds of Hogwarts are guarded by many ancient spells and charms to ensure the bodily and mental safety of those who dwell within them,’ said Snape.
’I still don’t = ’While you can still call home the place where your mother’s blood dwells, there you cannot be touched or harmed by Voldemort.
Voldemort, of course, had been obsessed with the possibility of hearing the prophecy ever since he regained his body; and as he dwelled on the door, so did you, though you did not know what it meant.
Harry had not thought about those words in weeks; he had been too absorbed in what was going on at Hogwarts, too busy dwelling on the ongoing battles with Umbridge, the injustice of all the Ministry interference… but now they came back to him and made him wonder… Voldemort’s anger would make sense if he was no nearer to laying hands on the weapon, whatever it was.
’If it hadn’t been for her…’ Ron went into a rant about Marietta Edgecombe, which Harry found helpful; all he had to do was look angry, nod and say ’Yeah’ and That’s right’ whenever Ron drew breath, leaving his mind free to dwell, ever more miserably, on what he had seen in the Pensieve.
Harry received two more ’D’s in Potions; he was still on tenterhooks that Hagrid might get the sack; and he couldn’t stop himself dwelling on the dream in which he had been Voldemort — though he didn’t bring it up with Ron and Hermione again; he didn’t want another telling-off from Hermione.
He and the DA were resisting her under her very nose, doing the very thing she and the Ministry most feared, and whenever he was supposed to be reading Wilbert Slinkhard’s book during her lessons he dwelled instead on satisfying memories of their most recent meetings, remembering how Neville had successfully disarmed Hermione, how Colin Creevey had mastered the Impediment Jinx after three meetings’ hard effort, how Parvati Patil had produced such a good Reductor Curse that she had…