For a solitary person who has led an active and involved life, a DNR might make sense if the alternative, maybe existing largely dependent or incapacitated for several long years, is unthinkable. Without strong ties to individuals with whom you'd like an extended and high-quality relationship (you have to think about what 'high quality means for you and for this exercise), or not wanting to be a burden to someone, the DNR makes a lot of sense.

Essentially....do you have a lot to live for? Will that still be sufficient if you are confined, bed-ridden, need to haul around machines or detectors, need others to take you places or to do manual chores and personal hygiene for you? Would you be okay with a year, six years, sixteen years, having to take six-ten drugs each day, some of them twice, to be conscious 12 hours each day, but little else?

For me, when I simply do not wish to keep struggling, when the intrusions of all kinds (as I define 'intrusions) are too much, when I become exhausted, or when living just ain't fun no more, then the DNR goes into effect when I say it does, witnessed, or when the designated trusted person who can legally put it into effect on my behalf, says so. In British Columbia, where I live, we have Powers of Attorney, Representation Agreements, and Advance Care Agreements. They're all legal, they all require sober forethought, and they all rely on the good will and savvy of a trusted adult to fairly and honestly represent the person invalided or incapacitated.

I don't mind heroics, especially if the care they intend is not going to leave me with a breathing tube for life, or on my back for life, unable to lift a TV remote on my own or to clean my own butt. Any of those taken away from me, hand me the cord and I'll pull it meself.