Me and a friend used to have this game when we back to class after the break. We would be shoving each other to wall with some shoulder pushes. Obviously, two teens in a contest like this tend to overpower each other. So when we were on the last floor i pushed him with all my might against the wall where people hang their jackets. His shoulder hit those coat racks really hard. So, with all the adrenaline in him he launched for me, smashing the both of us against the wall.. Only there was no wall, only the window of the classroom before ours. All i could do was stretch my arms to not go face forward. When my hands hit the glass it shattered immediately. We were just standing there, staring at a classroom full of people with a WTF expression on their face.