Why is frictional unemployment inevitable in an economy characterized by imperfect job information?

You know how when you first get a job and havent worked there and you're all excited cause it's the perfect job? And then when you get there you realize that it sucks and it was nothing like they told you it WOULD be? That's basically the reason. People are always going around searching for a perfect job because the job that they have isnt exactly what they want, or they are overqualified for it. So there is always some unemployment due to people looking for better jobs or moving around the country to other better jobs|||Because we are humans, therefore imperfect. For that reason, someone somewhere will always be in the wrong job, so they will bne quitting or getting fired, therefore...unemployed. Furthermore, companies are run by humans, so they are imperfect also. Therefore, they will always be doing GM-like things (realizing they are overpaying a bunch of lazy old fart union members to do what some Mexican or Korean will do for 10 cents on the dollar). They will lay off a whole bunch of people, then try to figure out how to do it better with different people. Of course, if it is GM, they will probably fail b/c they deserve to for still making Pontiacs - BLEK!