I think it comes from the statistical expectation. Like, if you were able to donate your kidney any amount of times, you would on average expect to lose your li

I think it comes from the statistical expectation. Like, if you were able to donate your kidney any amount of times, you would on average expect to lose your life on the 3,000th donation. So the question is, do you want to be the kind of person who would do that at the cost of your own life?