Why is it always SF?

A few of the blogs I read have mentioned this epic smackdown, in which an actual SF soldier smacks down a wannabe.
Why is it that all the wannabes always claim to be Special Forces, Rangers, Marine Recon, snipers, or some other “elite” subset of the military? They’re never humvee mechanics, radio repairmen, or the like.
Sure, I was in the military. I drove tanks. I needed a break from the hum-drum life of fixing computers and twiddling around in college without knowing what I wanted to do with life, and tanks seemed to be sufficiently different to interest me. I accomplished exactly zero acts of valor in my service, and managed to avoid any dishonorable deeds. I did my job, kept my head down, and stayed out of trouble. When my unit was training up to deploy to Iraq, a medical issue developed (( Bones in my feet started making fun happy grinding sounds. )) that prevented me from deploying. The army and I agreed that, due to this medical issue, it wasn’t in our mutual best interests for me to stay in, and I was discharged (( Honorably, for what it’s worth, though I don’t really think I did anything that justifies such a lofty adjective. )).
After I got out, I went back to college, got my degree, got a job, got married, and am looking to go to grad school (after which I’ll probably end up in a lab for the rest of my life, which is just fine with me). Not terribly exciting, which is why I suppose most of these poseurs never claim to be a lowly PFC who drove tanks around for a few years.