Situation:
You have a brain tumor. Any sort of chemotherapy is not an option. In fact, there is only one option that will keep you alive. You need to have surgery to extract the tumor. Absent surgery, you would live 3-7 years with the last 10 months or so dedicated to dealing with the final stages of the tumor. Surgery offers a 90% chance of survival BUT also a 90% chance of permanant brain damage. The tumor is too far in and too entwined with the rest of the brain matter to for the surgeons to really believe they can extract it without giving you an inadverdant lobotomy. The degree of brain damage is more or less an unknown factor but the odds are stacked more heavily towards moderate to severe brain damage than light brain damage. (An outside chance exists that you'll be rendered a vegetable)
Your family wants the surgery. They are adament about not losing you and have promised to care for you if you emerge with some form of retardation. The implication here though is that they WILL NOT allow you to commit suicide if the surgery goes badly so you would have to live with the results. (unless you retain enough motor control and intelligence to bypass this.)
The decision is yours; do you take the guarenteed 3-7 years existing as the person you are and dying as that person or do you opt for surgery and take the much longer lifespan living in a diminished state if you are are among the 81% of the people who both live and are damaged in the process.
Do you take the surgery and pray that you are one the lucky 9 of 100 people to walk away the same as they came?
Who are you and what do you value?