2. The following quote is from Donald Rumsfeld, Secretary of Defense under President George W. Bush from 2001 to 2006:

Reports that say that something hasn’t happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don’t know we don’t know.

Discuss this quote in the context of risk and uncertainty.