I suppose never die of injury or disease, because that means I wouldn't get Alzheimers or anything unpleasant as I got older!
A train has lost all capability of stopping, and it's headed straight towards a whole group of workers that are on the tracks (which are suspended high up in the air, meaning they cannot jump to safety). There is a lever in front of you, and if you pull it, it will divert the run away train down another path. But a friend of yours just climbed up on that track a few minutes ago, and if you pull it, they will get hit. But the 9 other workers will be sparred.
Would you rather do nothing, and allow the workers to die, or would you rather pull the lever to save them, thus condemning your own friend to death?