My nan always told us "if I get like that, shoot me" meaning if she deteriorated so she didn't have a good quality of life. When she had a stroke and the doctors told us she would never recover the ability to speak, eat or move by herself again, and they wanted to take her off oxygen and IV nutrients and let her pass away, it made the decision obvious if not easy. She would have hated being trapped in a broken body without being able to communicate, but it was very unlikely she would even have been aware of it because so much of her brain was dead. I feel like we got off really easy, we were given the option to let her die. I feel very sorry for people who know their loved one doesn't want to be alive any more, but are restrained by law from giving them what they want.