After retiring from the Army, a former artillery sergeant took a job as a high school teacher.
He injured his back just before the school year started, He was required to wear a light plaster cast around the upper part of his body.
Fortunately, the cast fit snugly under his shirt and wasn't noticeable when he wore his suit jacket.
On the first day of class he found himself assigned to the toughest students in the school. The smart-assed punks, having already heard the new teacher was a former soldier, were leery of him and he knew they would be testing his discipline in the classroom.
Walking confidently into the rowdy classroom, the new teacher opened the window wide and sat down at his desk. A strong breeze through the window made his tie flap. He picked up a stapler and stapled the tie to his chest.
There was dead silence. The rest of the year went smoothly.