A chair's function is not just to provide a place to sit; it is to provide a medium for self-expression. Chairs are about status, for example. Or signalling something about oneself. That's why the words chair, seat and bench have found themselves used to describe high status professions, from academia to Parliament to the law.
It's hard to describe what it's like to live with a concussion. You want to enjoy things like you used to, but you can't. You wake up in the morning and wonder how you're going to feel that day: What will my reactions be like? Will I have a headache? Will I have to triple check to see if I unplugged the flat iron?