The Value/Probability Tradeoff
Suppose you are trying to decide between enjoying an ice cream cone and buying the new novel you have been wanting to read (you cannot do both). The bookstore and the ice cream store are side by side, and you are standing in front of them. You are sure the bookstore has the novel, and you are equally sure that the ice cream store can provide you with ice cream you will enjoy. Is the expected benefit of going into the bookstore greater, less than, or the same as the expected benefit of going into the ice cream store?
The probability that the bookstore has the novel and the probability that the ice cream store has ice cream you enjoy the same, so the expected benefit of each action depends on the extent to which you value the novel and value the ice cream cone.