Killing Intent from Vanity

I woke up in the hospital with no memory of the previous day. I learned that I fell down the stairs. After I was discharged from the hospital, I secretly began to investigate the truth behind my fall down the stairs. Why did I have to go down the stairs far away from the toilet and classroom when I went to the toilet, instead of the stairs closer to the toilet and classroom. Why did everyone behave a little abnormally after I came back from the hospital: Why does Li Yaolu always avoid Qi Yuqing? Why do some people get flustered when I ask what happened before I fell down the stairs? I even began to avoid asking such questions. What happened the day I fell down the stairs?