Stolen from ElReg comments (an oldie but goodie, annotated):

Re: I am 52 I can’t wait to retire

Little Johnny is at school when the teacher asks each student what their father does for a living.

One child says, “My dad is a doctor.”

Another says, “My dad is a firefighter.”

When it’s Johnny’s turn, he says, “My dad is a piano player in a brothel.”

The teacher is shocked but moves on. Later that day she calls Johnny’s father to discuss the comment.

Johnny’s father sighs and says, “Look ... I’m actually a Microsoft support engineer. But I didn’t want my son to be embarrassed in front of the class.”

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The GF knows the drill and backs the story - I completely lie about what I do for a living when I meet people. If I tell them I work in IT, the first question is "I have a problem, $X_MS_PROGRAM, does $Y_ANNOYING_THING, how do I stop it?" and expect free support, for life.

My answer in similar circumstances used to be: Two hundred quid an hour; the first week up-front and non-refundable; and I'd be learning on the job.