Give an example you can relate to the marginal cost, marginal benefit model going on in your life.Be clear about what costs and benefits are involved.

Example: I brush my teeth because when I choose to do thateach day, the benefits of clean and healthy teeth outweigh the costs of 3 minutes doing my next best choice (probably surfing facebook). After a couple of minutes at this, the benefits of additional time brushing go down below the opportunity cost of giving up facebook, which stays the same. And so I stop