The train was about to pull out of the station. A young man ran towards it and managed to throw his bag in and climb aboard just in time.
A fellow passenger looked at him and said, “Young man, you should be in better shape! At your age, I could catch the train by a gnat’s whisker and still be fresh. Look at you, panting away. “
The young man took a deep breath and said, “I missed this train at the last station. “
This joke is included in the Black Book of Jokes. You can order it from here.