I guess I am lucky, because I have never seen one of these, but I understand. I would shake my head too, or roll my eyes too.
I used to see them while I was in L.A. but every once in awhile I’ll see them in places you wouldn’t expect. But mostly I’ll see them on TV being worn by some idiot. Also I remember his picture was in the background of a photo of some democrat on TV being interviewed awhile back. Che is a mythological creation.