I'll just never understand it. When you make a vow to grow old with someone there's an inevitable assumption that medical issues will show up somewhere down the line. How can anyone stand the thought of not being able to take care of their spouse if it happens to them? Or conversely, how can they stand the idea of watching their spouse's despairing failure to do so. Because it's not even a question at that point. Neither of them could take care of the other. God, imagine them trying to support the other's weight to get them to the bathroom or something.