'Which person,' she said, her voice shaking, 'which abysmally foolish person wrote down this week's passwords and left them lying around?'
There was utter silence, broken by the smallest of terrified squeaks. Neville Longbottom, trembling from head to fluffy-slippered toes, raised his hand slowly into the air."
Harry Potter and the Prisoner of Azkaban
The book frames this as a moment of disgrace for Neville, but I think it’s one of his most shining moments.
Owning up to such a catastrophic mistake in front of his entire House while Professor McGonagall stood there quivering with rage and practically breathing fire at him, when he could have just as easily remained silent without anyone ever being the wiser?
That took courage. And integrity.