This article (link) describes 20 flaws, biases, and causes of bad behavior when people deal with money. It's a great read. Here's my favorite (#5). It illustrates how our personal context can influence our view of the world – in this case being mostly optimist or pessimist about the stock market.

“Your personal experiences make up maybe 0.00000001% of what’s happened in the world but maybe 80% of how you think the world works. If you were born in 1970 the stock market went up 10-fold adjusted for inflation in your teens and 20s – your young impressionable years when you were learning baseline knowledge about how investing and the economy work. If you were born in 1950, the same market went exactly nowhere in your teens and 20s:”