Self-inflicted Zombie

One day I took an icepick And jammed it in my head The funny thing about that Was it didn't make me dead So I cut in deep around the top Then I scooped out my brain Now I had nothing in my head Did that mean I was insane? I guess that I'm a zombie Of a very different kind Self-inficted brainless dude It appears I've lost my mind But that doesn't bother me As I still pass the hardest test The whole world has gone crazy So I finally fit in with the rest