About 3 years ago I was out, drank way too much- blacked out and at some point fell on the pavement, hitting the back right side of my head. I had short term memory loss for a couple days following, then was fine. However, after all this time I still have a small bump in that spot on my head. Should I see a doctor? As it healed I picked at it....dumb, I know. So I don't know if it's the skin that healed back thicker, or my head is messed up. All cognitive abilities in check. Thoughts?