I spent months wearing a helmet, with bone flaps completely removed from both sides of my skull and placed under the skin on my abdomen. I spent about 3 months in that state, then had another brain surgery to replace the bone flaps.
Substantial atrophy resulted in a complete inability to walk, and it's left substantial scarring across much of my head. The cosmetic effects are quite noticeable, but I also lost my sense of smell. It was a hard thing to go through as a teenager, but it's had a substantial impact on the way that I approach life in adulthood.