That's pretty enlightening. This guy is brilliant because he constantly reminds himself of the fundamentals of business, and is keenly aware that he easily gets off track from those fundamentals.
It seems as humans, we're very prone to forgetting the most basic of lessons, and unless we constantly refresh on them, we can easily get off track. It puts things in perspective like the whole Qwikster/Netflix debacle, or the recent talk of bloat at Google. At a very basic level, these issues are signs that the people in charge may have gotten so caught up in the day to day that the lost their "firm grasp of the obvious". Since in both cases the mistakes are "obvious" to people on the outside.