I made an oath to myself a long time ago that the only thing that will kill me is myself. Screw nature.
Well it's not like magic kills you. If you die of cancer, it's
your body doing that. If someone blows your head off, it's
your brain being destroyed that kills you. The only thing that truly kills you is yourself, the cause of the effects is irrelevant at that point. If you mean you want to consciously end your life, then by all means, have fun.
I haven't the slightest idea of what I'd do. I know when I'm old this time will come, when I realize I'm going to die soon, and there would likely be no fun way to spend my time by then - due to the deterioration of my body at that point.