A bit of old parchment!' said Fred, closing his eyes with a grimace as though Harry had mortally offended him. 'Explain, George.'
'Well...when we were in our first year, Harry-young, carefree, and innocent-'
Harry snorted. He doubted whether Fred and George had ever been innocent.
'-well, more innocent than we are now-we got into a spot of bother with Filch.

Author: J.K. Rowling