Galen, my aunt virtually did that. She ended a long nursing career as head of the nursing school in a big hospital in London.
In old age and fully in command of her faculties she had a number of serious medical conditions that inter related. She was never in care but her GP ended up prescribing, more or less, to her diktat. Not I think because she was overbearing or unreasonable but because she knew as much about her conditions as he did and was actually living with them so had a very exact idea and understanding of how her medication affected her and how to adjust it for her better welfare.
She lived to within a month of her 87th birthday despite having had serious medical problems throughout her life from childhood, so clearly had everything well under control.
Shall we reboot our cartoons thread again? 😁
To think that London, or anywhere else for that matter, does not belong to any one demographic