That year, on a late summer afternoon, during some class, a few clear bird calls came. When I looked up, a chubby bird stood on the window frame of the classroom with curious eyes and swayed its head towards us looking around. Some active boy unconsciously stood up and leaned over. This move startled the bird, the bird jumped into the classroom in a panic, and fluttered in the limited space. In an instant, the entire classroom was boiling, the boys were almost all excited, and immediately closed the doors and windows and started hunting the bird. The girls, on the other hand, were mostly panicking, covering their faces and hiding their heads when the bird flew over their heads or was bumped by the boys. Suddenly the classroom was filled with the crying of the bird, the screams of the girls, the laughters of the boys, the falling of books and pencil cases, and the loud noise of desks and chairs being turned over… After a while, the door of the classroom was opened by someone. The bird saw the opportunity and with a long whistle, soared into the sky, leaving only a group of us watching the bird flying away. After that, it seemed no one cared much about what was said in that class anymore. From time to time, some classmates would lift their heads and look out of the window thinking. This little episode has long been forgotten with the aggravation of studies and then the graduation. It was not until the first class reunion after more than 20 years that we all mentioned it, and only then did we realize that we were really envious of the free bird from the bottom of our hearts as we were under strict control.