> the marginal utility of one glass of water, or one screw in a more complex utility function (as is always the case in life) than for just one widget, I was t

> the marginal utility of one glass of water, or one screw in a more complex utility function (as is always the case in life) than for just one widget, I was taught the concept using the water example in undergradudate, and find the analogy is spot on. Other comments are considering more complicated marginal effects or the intersection/equilibrium of multiple marginal effects and confusing the point.