Have you noticed that all it takes is one bad event to completely ruin an otherwise wonderful day? Why do we devote so much brain power to fixating on the negative when we’d be so much happier by fixating on the positive? It all comes down to evolution. Because of the life-threatening nature of many negative experiences, we have evolved to give them higher value and stronger hold in our memory. When you learn to dodge a bullet, you can’t forget that experience in case another one comes at you.
Read more about the experiments that compared real world scenarios of good and bad to see how people as a whole respond, in my article published on That’s Life [Science].