I was Reading through notes I took about six months ago during a talk given by a CEO of a large company, who was fired by his board because his firm had serious performance problems -- and was taking great risks -- that he never learned about until it was too late, and the firm was in deep trouble.  I can't identify him, but as I have warned here, at HBR,and in Good Boss, Bad Boss, every boss risks living in a fool's paradise -- and the more power the boss wields over others, the greater the risk.

Here is his comment:

"You desperately need a candid adviser.  When you become CEO, you get a lot of bullshit.  You don't information so much as you get sales pitches.  You're alone in the ring."

This guy learned the hard way; I offer it so others can avoid the pain and obvious embarrassment he felt.  He looked like wounded animal during this talk, but I had to give him credit for being honest.