"Never mind that, do you think he remembers what You-Know-Who looks like?"
Their mother suddenly became very stern.
"I forbid you to ask him, Fred. No, don't you dare. As though he needs reminding of that on his first day at school."
This is from the book Harry Potter. I had a hard time to understand the sentence in bold above.
"As though" looks strange.
The usage of "reminding of" is unusual and it's typically used as "reminding sb. of sth.".
It looks like a incomplete sentence and there seems something that has been dropped.
Can someone help me to understand the sentence?