J. K. Rowling Quote
Professor, why couldn't we just Apparate directly into your old colleague's house?' 'Because it would be quite as rude as kicking down the front door,' said Dumbledore. 'Courtesy dictates that we offer fellow wizards the opportunity of denying us entry.
Harry Potter and the Half-Blood Prince (ed. Pottermore, 2015) - ISBN: 9781781100257