What mistakes did the people in the ancient text "He Geng" make?

Original text: If a person has a soup, he can taste it with a ladle. If there is less salt, it will be better. Later, when he tasted it again and put it into the ladle, he said: "There is not enough salt." If you count it like this, you will get more salt, so it is not salty, so it is strange.

Translation: A man prepared a pot of soup. He first took out a spoon and tried to taste it. He found it tasted bland, so he added some salt to the pot, and then tasted it in the spoon again. He still felt that it was tasteless. It tasted bland, so he said: "Not enough salt!" I added about a liter of salt several times, but it was still not salty, so I thought this was strange.

This is a joke. His mistake was that when he added salt to the pot, he tasted the soup in the spoon from the original soup. In fact, no matter how much salt he added to the pot, it would not taste good. Change the taste of the soup in the spoon