My death is not my own – the limits of legal euthanasia

TL;DR:

"This is the catch-22. If your dementia is at such an early stage that you are mentally fit enough to decide that you want to die, then it is probably “too early” to want to die. You still have good years left. And yet, by the time your dementia has deteriorated to the point at which you wished (when your mind was intact) to die, you will no longer be allowed to die, as you are not mentally fit to make that decision. It is now “too late” to die."