The main theme of "Contents of the Dead Man's Pocket" is the importance of living and enjoying life in the moment, because, in the end, life is short.
This theme is summed up in a different way by Tom's wife, who says, as she leaves her husband to go to the movies,
You work too much, though, Tom—and too hard.
Tom is an ambitious young employee at Wholesale Groceries. He wants to get ahead and is doing so by working on new ideas for the grocery business. For two months he has been going into grocery stores and counting shoppers on weekends, on his own time, and is now ready to compile a report about his findings and how they should influence the new displays. He feels that all this extra work will help him rise to the top level at his company, which is where he wants to be.
However, after the paper with his careful research on it flies out the window of his upper-story apartment and he risks his life climbing out on the window ledge to retrieve it, only to have the window crash down behind him, Tom has a genuine, terrifying brush with death. Upon realizing that he has nearly died in an effort to get ahead at work, Tom vows to no longer make work his top priority. He now sees the value in spending more precious time with his wife.
Afterwards, when he is safe and the paper once again blows out the window, Tom laughs, uncaring. He goes to join his wife at the movies: he has learned his lesson. Life is too short and too fragile and precious to waste in the rat race of getting ahead. We can feel assured that, from now on, Tom is going to try to enjoy life as well as work hard.