More illogic: either you are a "vegetable" or not. If you are in a vegetative state, what does it matter to you who wipes your butt?
In the meantime, make your Advanced Directive, set up your Durable Power of Attorney, don't smoke or drink, eat very carefully to maintain a healthy weight, keep your cholesterol in check, and chew each bite carefully, watch your step and the driving of others and stay off ladders. Watch very carefully for homicide bombers and snipers and hand over your watch to the mugger - and hope he's more honorable than Michael Schiavo.
I'm sure I haven't covered all the ways you could reach a state of decreased mental functioning, but if you are very careful, you may not live at full function forever, but it will seem like it.
These sort of meanspirited comments are unecessary.
You should watch carefully for fanatics who would maintain your existance in the most horrible state of suffering, because they think by not letting you go they are being pro-life heros.