"The bigger the file, the bigger the smile" Mr Barnard MOD apprentice training centre 1987
Told to every young engineer being overcautious with his file choices
Another, but specific to that training centre... "That has a wee in it, you'll see it better in daylight"
Goes outside offers it up to the light, professionally perusing it's surface, then throws it as far as he can into the woods whilst shouting "weeee"
Mr White I believe he was called