Why do people say half a dozen?

Why can't they just say Six

What's the difference between Dubai and Abu Dhabi?

People in Dubai don't like the Flintstones but people in Abu Dhabi doooooo.

Why do people studying engineering get to already call themselves engineers?

It is not like that anywhere else. It is not like people studying science claim that they are already scientists. Or people studying the arts say they are unemployed.

Half Dozen Jokes More Half Dozen Jokes

Why do people say half a dozen?

Why can't they just say Six

What do you call it when your computer gets infected with a keylogger, a rootkit and half a dozen backdoors?

A free upgrade