Oftentimes, after an event has occurred, we look back on the past thinking that the outcome was obvious. We believe that we could have predicted the end result before it happened. This phenomenon is called the hindsight bias.
I have never had good luck with randomly assigned roommates. To try to prevent a horrible year, I asked a girl that I knew from home if she would room with me. We got along pretty well for most of the year until she had an emotional breakdown in our kitchen. I got a text from my other two roommates that the girl had started throwing plates and screaming profanities. She had become a madwoman.
Looking back on the event, I convinced myself that I had seen the breakdown coming before it happened. There were a few instances of emotional instability that pointed to a future catastrophe. However, after learning about the hindsight bias, I realize that I had no idea that something so explosive was going to happen. I had attributed all smaller breakdowns to bad days or her having a hard time with school. It was not until after the event occurred that I had patted myself on the back for seeing something like that coming. I had seen the small instances as clues pointing to the bigger event. She may have been a bit crazy, but I was deluding myself into thinking I knew the meltdown was coming all along.