In the late 19th century, there was a common tradition in American bars where they would offer a “free lunch” to people who purchased a drink. Although it seems like a good deal at face value, the lunches offered were quite salty, meaning that eating it will make you thirstier for another drink. On top of that, the price of the drinks would usually more than compensate for the price of lunch, while making the patron think he or she got a “free lunch”.
This is the free lunch referred to in the saying: “There ain’t no such thing as a free lunch”. Nothing in life is free. If someone tries to tempt you with a free product, there will no doubt be a string attached in one way or another, such as a hidden cost. To have something, you must trade in an equal amount of something, such as time, money or work, or take it from someone else. Because you cannot make something from nothing. Such is the way of the universe.
Every resource is finite, meaning that you must make choices on how to use these resources. Every decision comes with an opportunity cost – the cost of not being able to use your resources for a different outcome. If you have $2, you can buy a bag of chips or buy a drink, but you cannot have both.
The most useful application of this principle is time. When you procrastinate or leave your work to tomorrow, you are not having a “free lunch” in the sense of having free time to yourself. You are borrowing that time from the future, as you will no doubt pay the cost of having to work harder or end up with a less comfortable life.
If that is the case, then how are we supposed to have the time to keep ourselves happy, when we have so much work and so little time? Economically speaking, the only way you can have anything close to a free lunch is by improving your efficiency. By being efficient, you reduce the time you spend doing work and you can gain more happiness while investing less time. For example, instead of procrastinating watching television, if you engage in your favourite hobby and enter a flow state, you will achieve far greater happiness for the same amount of time.