It takes two

At work we had one of those know-it-all managers. He's since retired, and it was a huge loss of experience and knowledge, because between the two of us we knew it all.

He knew everything in the world except that he was an idiot.

And I knew that.

Update: My gratitude to all who didn't comment on the incorrect spelling of 'knowledge' above. I said I only needed to know one thing...