When generals or admirals walk into our area, the first marine who sees them is supposed to yell out "ATTENTION ON DECK!".
One day I was busy working near the door and a 3-star walked in. I was so caught off guard and with my mind on my work but with the need to respond that I snapped to attention and yelled out "HOLY SHIT!"
Needless to say the General died laughing and didn't mind at all. His aide (a captain) was much less amused.