Themes
Fame is a fickle friend, Harry.
— Gilderoy Lockheart · Harry Potter and the Chamber of Secrets

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Lockheart tells Harry that fame doesn't stay loyal. Its attention comes and goes, so it can't be relied on like a real friend. It's breezy worldly advice about not leaning too heavily on public admiration.
Context reviewed