James Potter-Evans-Verres.
Harry added their current address, then folded up the letter and put it in an envelope, which he addressed to Hogwarts. Further consideration led him to obtain a candle and drip wax onto the flap of the envelope, into which, using a penknife's tip, he impressed the initials H.J.P.E.V. If he was going to descend into this madness, he was going to do it with style.
Then he opened his door and went back downstairs. His father was sitting in the living-room and reading a book of higher math to show how smart he was; and his mother was in the kitchen preparing one of his father's favorite dishes to show how loving she was. It didn't look like they were talking to one another at all. As scary as arguments could be, not arguing was somehow much worse.
"Mum," Harry said into the unnerving silence, "I'm going to test the hypothesis. According to your theory, how do I send an owl to Hogwarts?"
His mother turned from the kitchen sink to stare at him, looking shocked. "I - I don't know, I think you just have to own a magic owl."
That should've sounded highly suspicious, oh, so there's no way to test your theory then, but the peculiar certainty in Harry seemed willing to stick its neck out even further.
"Well, the letter got here somehow," Harry said, "so I'll just wave it around outside and call 'letter for Hogwarts!' and see if an owl picks it up. Dad, do you want to come watch?"
His father shook his head minutely and kept on reading. Of course, Harry thought to himself. Magic was a disgraceful thing that only stupid people believed in; if his father went so far as to test the hypothesis, or even watch it being tested, that would feel like associating himself with that...
Only as Harry stumped out the back door, into the backyard, did it occur to him that if an owl did come down and snatch the letter, he was going to have some trouble telling Dad about it.
But - well - that can'treallyhappen, can it? No matter what my brain seems to believe. If an owl really comes down and grabs this envelope, I'm going to have worries a lot more important than what Dad thinks.
Harry took a deep breath, and raised the envelope into the air.