Expertise

There are as many opinions as there are experts.

—Franklin D. Roosevelt

If the world should blow itself up, the last audible voice would be that of an expert saying it can't be done.

—Peter Ustinov

Expert: a man who makes three correct guesses consecutively.

—Laurence J. Peter

An expert is a person who has made all the mistakes that can be made in a very narrow field.

—Niels Bohr

I know a lot about cars. I can look at a car's headlights and tell you exactly which way it's coming.

—Mitch Hedberg