Conversation so far:
How did Lord Voldemort's character begin?
In a 1999 interview, J. K. Rowling said Lord Voldemort was invented as a nemesis for Harry Potter, and she intentionally did not flesh out Voldemort's backstory at first.

Question: Why did Rowling do that?
Self-contained rewrite: Why did J. K. Rowling not flesh out Lord Voldemort's backstory at first?