Sometimes it's hard to know when to stop
An old man went to the doctor and began to pour out his problems. As the doctor asked more about what was the matter with him, the old man said, "Well Doc, after I get to the first, I'm very, very tired. After the second, I feel all in（疲乏到极点）. After the third, my heart begins to pound. After the fourth, I break out in a cold sweat. And after the fifth, I'm so exhausted, I feel like I'm going to die, right then and there（当场）!"
"That's incredible," said the doctor, "but how old are you?"
"Eighty-five," the patient said. And the doctor said, "Well, at 85, why don't you stop at the first?"
The man said, "I can't stop: I live on the fifth floor!"
一个老人去看医生，滔滔地讲述他的问题。医生进一步询问他的症状，他说：“医生啊！我上第一层之后，感到非常累！上了第二层，觉得快不行了！到第三层，心跳加剧！到第四层，大冒冷汗！到第五层，筋疲力尽， 感觉当场就要死了！”
“真不可思议啊！”医生说：“你今年几岁呢？”
“八十五”，病人说。医生说：“噢，八十五岁了！为什么你不一开始就停下来？”
老人回答：“我不能停下来，我住在第五层楼啊！”