You're kidding right? What you're suggesting is that if one decides to commit suicide, and has it "notarized," one then surrenders the ability to change their mind at the last minute...but you and those on your end of the argument insist that suicide is all about personal choice. What you are talking about is essentially hiring a hit man to take yourself out, and have a court witness the validity of the contract!! Do you realize how insane this is?
Like everything else in the left's agenda, the arguments in favor of euthanasia are entirely emotional with almost no basis in either fact or reason.
It is absolutely sane in a non-religious frame of reference. And I am not kidding in the least.