User blog comment:Jspyster1/Edd's Hat (Theories)/@comment-72.188.113.236-20110416100654

Double D is very clearly suffering OCD in the series. Many people who have this disorder will actually scratch their scalp to the point of injury, and even pull their hair. This explains the "Does it hurt?" line from Ed as well as Double D's only 3 strands of hair that we see sticking out of his hat. He's probably got bald, scratched up patches on his head(not completely bald, mind you). A sad theory, yes, but I think it's pretty logical.