To all teachers who come in class at the last second, WHY???

Can't you we were all ready to go??!!! Can't you see we were all hoping that you wouldn't be here???

We're all there in front of the classroom looking at the time waiting for the 15 minutes to pass so that we can legally leave and you dare arrive at the last minute???!!! How dare you! 

PS : in France, students are free to leave for the hour if a teacher is 15 minutes late for class.
I don't know if that goes in any others countries