Concussion can and does kill. It killed my sister when she was knocked off her bike and hit her head on the kerb.
Another friend of mine was off work for well over a year after a road accident, She was the front seat passenger, the car spun and she hit her head against the door pillar.
Another friend has had a couple of falls wher she did not hit her head but the sudden jerk of her neck caused mild concussion and she now has long termpost-concussion syndrome www.nhsinform.scot/illnesses-and-conditions/injuries/head-and-neck-injuries/post-concussion-syndrome-pcs/
I write all this because I feel most people on this thread are treating concussion quite lightly, when even mild concussion is a serious injury that can cause long-term health effects, including being a long term catalyst for dementia. You do not need to be a footballer who did lots of headers, for concussion to contribute to dveloping dementia
I am an admirer of Princess Anne, but I think she treated what sounded like quite a serious concussion far too lightly. All though seeming back to normal in the public eye, I do wonder how long she suffered from other side effects, like headaches after her return to work.
I would want anyone who was as seriously concussed as she was to take a lot more than three weeks off. Being royalty does not protect you from the damage other people suffer after concussion and it is silly of her to risk her long term health just because she has a reputation to (now) being a tough old bird who carries on regardless that she wants to nurture.