I have a sense of self preservation that exceeds my standards.   Exactly why I couldn't be a healthcare worker or firefighter.  I'm not  going to  ruin my back for someone.  I'd rather they die than i endure lots of terrible pain.    If  they really wanted to live, they wouldn't have gotten that fat.  But that's just an ex post facto rationalization for me because I don;t want a ruined back.