weeks before she moved in with us my wife and SIL confiscated her keys when she didn't notice and they just let her believe they were lost. Stopping her from driving was long overdue. It's a miracle she didn't hurt anyone.
When she first moved in with us she could still talk (three months in she had a seizure and was never able to speak in complete sentences again). She had the feeling some mysterious "they" was preventing her from driving and she wasn't happy about it.
One day she was riding with my wife and kids when they stopped at an intersection. Another elderly lady who shouldn't have been driving rear ended our mini van and in her confusion she backed up, hit it again and then repeated the process one more time before she stopped her car (that's right three collisions in one). Our van wasn't the first car she had hit in that two minute stretch. Someone else called the police before my wife could.
The cop who came to investigate said the lady shouldn't be driving, but he didn't have the authority to take her keys.
When he left, my MIL angrily exclaimed, "If they let her drive I don't see why they won't let me drive." My oldest, who was 15 but not old enough for his learner's under the law at the time tried to diffuse the situation with humor. He said, "It's okay grandma, they won't let me drive either." Without skipping a beat she responded, "Well what have they got on you?"