Dan Ariely notes we’re pretty sure good things will happen to us and bad things won’t:

One of the most basic findings in behavioral economics is what’s called the optimism bias, also known as the positivity illusion, or overconfidence. When people judge their odds of achieving good outcomes — getting a good job, successful marriages, healthy kids, financial success — they generally estimate these odds to be higher than those of other people. Similarly, when people judge the odds of negative outcomes befalling them — a heart attack, a parking ticket, divorce — they estimate these odds to be lower than those of other people.

People have a tendency for overoptimism:

See also:
Alain de Botton
On Pessimism

[S]ociety as a whole often benefits from the decisions that result from overoptimism. It’s a version of the “thrift paradox,” in which spending a lot is bad for individuals but good for the economy as a whole. Imagine a society where no one takes on the risk of creating startups, developing new medications, opening restaurants, starting new businesses. We all know most of these fail in the first few years, yet they crop up all the time.

What will recent negative events teach us?

I don’t think we are in any way better, more thoughtful people — shining phoenixes rising from our fiscal ashes — but if we take these painful lessons to heart (and mind), we might create lasting changes in our environment.

I’m hopeful. Overly so.