Every time somebody describes their job, it sounds so cool. In my mind, it is sleek and brightly colored and either hilarious or badass. Then if I ever go and see the job in person, it is so remarkably underwhelming. The skills and responsibilities people put on their resumes may be 100% accurate, but the image it conveys is much different than the reality of it.
I know that I'm guilty of it, myself. I realize that it comes from both ends: the author and the audience. An author may choose to shade his or her life in a particular light. It can be conscious or unconscious. But the audience will also assume certain things based on their own preconceived notions. Whichever side you're on, you can't help what the other side chooses to do.
As a writer, though, you can make use of these things. Consider how differently you can describe an act that it may seem exciting or mundane. Consider the feeling you can create in people by talking about how great or exciting something is, then showing the underwhelming reality of it all. It's a great power. try exercising it.