The WSJ recently reviewed a book called “Billion Dollar Lessons”

Here is one of the stories from the book (and the review):

Some years back an outfit called Green Tree Financial Corp. soared into the stratosphere by making 30-year mortgages to buyers of trailer homes (instead of the standard 10 or 15 year mortgages on trailer homes).

From 1991 to 1997, a span in which Green Tree’s chief executive was paid $200 million, the company’s stock shot up 30-fold. But since all the relevant players at Green Tree made their money by signing off on loans, no one paid close attention to the inconvenient fact that trailer homes, unlike houses, do not increase in value over the long run. On the contrary, trailers depreciate rapidly and last only 10 or 15 years, by which time a 30-year loan isn’t close to being paid off. So after just a few years, Green Tree borrowers discovered that they owed far more than the underlying asset was worth. You can imagine how all this turned out. …..

The basic premise is that there is much we can learn from mistakes, although it is clearly very painful.