J.k. Rowling said this quote

Excellent,” said Lupin, looking up as Tonks and Harry entered. “We’ve got about a minute, I think. We should probably get out into the garden so we’re ready. Harry, I’ve left a letter telling your aunt and uncle not to worry —” “They won’t,” said Harry. “That you’re safe —” “That’ll just depress them.” “— and you’ll see them next summer.” “Do I have to?