We face “trade-offs” in everyday life from dusk till dawn. Imagine that you have to make a decision about what to have for lunch. You may have several options with a limited budget and timeframe: you could go to a restaurant spending more money and time but having a good time with colleagues, or you could go to the university cafeteria where food might be worse but you spend less money, or you could even bring food from home to have a quick lunch. At every moment, we make a decision to increase our utility knowing that we cannot have everything at the same time.