Because I dropped a six pack of half a gallon juice on my head. While it was made of plastic, thus it bounced, my head and shoulder hurt and I feel dizzy. Do I have a concussion? Admittedly head injuries are not my specialty.

Update: So after sleeping for a few hours I think something in my neck is just sore. Here is hoping I just hurt a muscle or something. And no I won't be going to a doctor until I feel even worst then before.