Frank Mccourt said this quote

First day of your teaching you are to stand at your classroom door and let your students know how happy you are to see them. Stand, I say. Any playwright will tell you that when the actor sits down the play sits down. The best move of all is to establish yourself as a presence and to do it outside in the hallway. Outside, I say. That’s your territory and when you’re out there you’ll be seen as a strong teacher, fearless, ready to face the swarm. That’s what a class is, a swarm. And you’re a warrior teacher. It’s something people don’t think about. Your territory is like your aura, it goes with you everywhere, in the hallways, on the stairs and, assuredly, in the classroom.