You remember the past as better than it was, and expect the future to be worse than it will likely be.

Despite living in the most peaceful and prosperous time in history, many people believe things are getting worse. The 24 hour news cycle, with its reporting of overtly negative and violent events, may account for some of this effect. We can also look to the generally optimistic view of the future in the early 20th century as being shifted to a dystopian and apocalyptic expectation after the world wars, and during the cold war. The greatest tragedy of this bias may be that our collective expectation of decline may contribute to a real-world self-fulfilling prophecy.

Instead of relying on nostalgic impressions of how great things used to be, use measurable metrics such as life expectancy, levels of crime and violence, and prosperity statistics.