The story is told of a little girl named Liz who suffered from a serious disease. Her best chance of recovery would be to receive a blood transfusion from her five-year old brother.
The doctor explained the situation to Liz's little brother. He asked the boy if he would be willing to give his blood to his sister.
The young boy hesitated for a brief moment. Then he took a deep breath and said, "Yes, I'll do it if it will save Liz."
During the transfusion, the boy lay in the bed next to his sister. He smiled when he saw color returning to her cheeks. But then his smile started to fade, and his face grew pale.
With a trembling voice, he looked up at the doctor and asked, "Will I start to die now already?"
The little boy had misunderstood the doctor's explanation. He thought that he would need to give all of his blood to save his sister...and he would have done so.