You're involved in a car accident, and there's fire getting closer to the gas tank. The other driver is dead, but her daughter is still alive. If you go back to the car and save the daughter, the explosion will permanently disfigure your face, scalp, etc, though the girl will live. If you run away from the accident, nobody will ever know that the girl was still alive and you will never be blamed for her death.
The girl will perish within 5 seconds of explosion and her pain will be very short lived, whereas my permanent scar will leave a physical, mental and emotional stress for the rest of my life. I don't see the point in doing something good if it means you have to be miserable, but I'd have this guilt in me that I didn't save the kid. I'll just see it as her karma or destiny that it was her way to die, or time to leave.