Final answer:
The phrase "There is no use crying over spilled milk" represents the sunk cost concept by implying that one should not focus on irrecoverable past losses but instead look toward future decisions. It parallels examples where individuals face the choice of continuing a failing investment due to emotional attachment versus making rational decisions based on future costs and benefits.
Step-by-step explanation:
The phrase "There is no use crying over spilled milk" illustrates the concept of sunk cost by suggesting that one should not dwell on past expenses or efforts that cannot be recovered. For instance, if an individual invests money into a venture that fails, the investment is a sunk cost. Just as crying over spilled milk won't recover the milk, lamenting over the invested money won't bring it back. The practical approach is to focus on future opportunities rather than the costs already incurred.
Consider the example of Selena, who spends money on a movie ticket only to find the movie terrible after 30 minutes. She faces the decision: should she stay because she paid for the ticket, or should she do something more enjoyable? The money spent on the ticket is a sunk cost and her best choice should be based on what will bring her the most satisfaction moving forward, not on the money or time that has already been spent.