You can’t eat tap water without boiling it. You can’t eat apples without washing them. How can you eat apples that have been washed with tap water?

First of all, who tells you how to draw the line between what can be eaten and what cannot be eaten. Can’t you drink tap water? Yes, but the health disutility it brings to you is far greater than the utility you need to drink water under normal circumstances. To put it another way, you are almost dying of thirst. If I give you a sip of tap water, will you drink it? Of course you drink it. Your demand for water is so high at that time, who cares what kind of water it is? The same goes for unwashed apples, so I won’t elaborate further.

Next, let’s talk about why you can eat apples that have been washed under normal circumstances? Because after washing with tap water, most of the negative substances on the surface of the apples have been removed, and there will be a little bit of tap water remaining on the apples, but the amount of tap water is too small to bring any negative benefits. Insignificant when all things considered. In other words, the total number of negative beneficial substances remaining on the surface of the apple at this time is far less than your demand for an apple itself under normal circumstances. Right, so you chose to eat it.

Then the next step is to talk about the "relatively reasonable" approach. Wash the apples with purified or boiled water, cool them down, and then eat them. I believe very few people do that, yes, very few, but not none. After all, no matter how big the bird is, it can be found in any forest, right? Why so few people do that is because the economic or time cost of buying pure water or boiling water and waiting for it to cool is added to the other end of the scale. In other words, the sum of these costs is greater than your normal demand for an apple.

The rich can also consider whether to buy a few boxes of Evian for the nanny to wash the apples. Anyway, for the rich, the coefficient of economic cost in weighted accounting based on his needs is much smaller than ours. Normal economic class, so in his inequality, using Evian to let the nanny wash the apples is a very reasonable choice.

Maybe you will say that you didn’t think about it that much when eating an apple. However, this concept exists in your subconscious to a certain extent. People choose to do one thing and make it a habit. What is passed on must be the best choice based on the fact that this matter is in line with its own value system. It's just that you are used to it and haven't thought about it deeply. If you think about it carefully, this is true for many things in life.