People often seem to have a casual attitude to concussion; you read sports star X is out with a concussion and think little of it. Another word for concussion is "traumatic brain injury" and that tends to get it across better. I had a bad concussion a while ago and I still get occasional headaches, I had a tinnitus for months (if you are unlucky, it stays with you forever) and my sense of smell is permanently altered. I was ultimately lucky on that one too, enough force and you can permanently sever the connection to your olfactory receptors.
