Deus proposes that there is yet another variation: "the things that we are too lazy to know."
In the ongoing efforts to lay blame for the crisis, the post points to a lack of thorough analysis: "In 2006, some people — including some people I knew — knew that AAA RMBS were sensitive to house prices…However, they had not done the analysis to go beyond that, so they didn't know how sensitive some of these securities were to a drop in house prices."
Even here at BankThink we remember plenty of murmurings about "the housing bubble," and though a handful of contributors point back to I-told-you-so columns, these warnings didn't stop the party. Deus says this intellectual laziness is widespread in finance: "people are peripherally aware that there is more to be known about a topic, and that that knowledge is somewhat relevant, but they don't find out. They prioritize, they ignore stuff that's difficult; whatever."
You may have already had some inkling of that, but hey, now you know!