Once again this is simple failure to learn from history.

When one's entire lifetime has revolved around boom times and never seeing what happens when things go the other way their perception of reality becomes skewed. People tend to think they are smarter, more sophisticated or more advanced than those that went through the really hard times and that things like stocks and homes only ever increase in value.

Unfortunately most who went through the really rough depression years are gone, or not able to pass on that wisdom and experience.

My grandparents were born around 1900 so they went through the really tough times. It forever colored their views of things and it was something very harsh that they never ever forgot. It shaped how they lived the rest of their lives, and I am fortunate that I spent most of my youth around them listening to those stories and experiences. 

If you go back through the history of mankind this happens time after time.

A generation goes through this and suffers, they tell their children who may have also experienced it some as well. By the time their grandchildren and great grandchildren come around they just roll their eyes about the old timers story's while playing on their phones.They discount the opportunity of learning because after all "that was along time ago and it does not apply anymore"

The minute they allow that thought in their minds  means they will eventually be doomed to repeat them because they filed to understand the lessons from the past.

Human nature and human history repeats time after time because of the failure to learn from the past.