Over the years, you meet and work with a wide range of characters. Each one with its own goodness and flaws. Today, I'm talking about the "Smart Idiot Expert" (SIE for short).
These are the two key characteristics of the Smart Idiot Expert:
He is very smart, intelligent and has 10+ years of experience on his/her area;
He doesn't listen to others opinion, even more so if others are not experts on his/her area.
Have you ever worked with a designer that presented you with a logo, and you tell him that you think the dot on the "I" should be just a bit higher, and he tells you it shouldn't and is just right, even though 3 other people agree with you. That's an Smart Idiot Expert.
I don't mean to pick on designers, and you can find SIEs everywhere: Software developers (lots of them, who refuse to question their own great software architecture skills), UI experts, business consultants, marketers (lots of SIEs here as well), the IT guys, writers, photographers, salesmen, etc.
The opposite of that is when you work with somebody that is a 20+ years expert, unquestionably smart and he presents you with a solution, and you think something should be different, and he listens (!) to you and -- sometimes -- agrees with you.
Are you working with some Smart Idiot Expert? Lose'em. They don't listen to you and they don't listen your customer.