Exactly. Also, if you're a professional software developer, even your resume isn't a good description of what you are an expert on, so their one line description isn't adequate.
If I say I'm an expert on "linux", that could mean linux kernel code, the LAMP stack, or administration and then I get questions like "why do I not get sound out of my netbook on Ubuntu 9.10?"
If I say I'm an expert on "linux", that could mean linux kernel code, the LAMP stack, or administration and then I get questions like "why do I not get sound out of my netbook on Ubuntu 9.10?"