All our abilities and knowledge are gradually formed through constant experience accumulation, and in this process, what we often call "common sense" will also be formed. The conflict of common sense refers to the emergence of different opinions and viewpoints from what we are used to knowing. For example, on the question of "what's the use of shampoo", the usual understanding is to protect hair and improve hair quality. Anyway, it is inseparable from the category of "hair". However, if there is a shampoo at this time with the slogan "Shampoo washes not the hair, but the scalp", then there is a conflict of common sense. At this time, you are troubled by hair loss, dandruff and poor hair quality. Will you be attracted by this contradictory statement? Obviously, not only I will, but I will also try to find out why shampoo washes the scalp instead of the hair.