I agree with xanadu. I have not called my condition a concussion in ages. I say I have a brain injury. When people ask what happened or how I got hurt, I tell them it was too many concussions.

My comment will usually pertain to an event, task or environment. I might say, "I have a brain injury and don't process sounds properly" or "I have a brain injury and have very little short term memory."

Something that helps is to explain an extreme example of a symptom like, "I used to have a photographic memory but now I can not even visualize an image in my mind. I can look at you, turn away and only remember that you have a blue scarf on. I can't picture your face or anything else. "

Our daily struggles that they take for granted usually make an impression.