In previous times, people didn't have many of the same products, lifestyles or environments that we do these days! In recent times, we have made use of conditioners, treatments, and styling products that leave residues, which can only be removed with a strong surfactant. Personal care in general has evolved in many ways. For example, people once cleaned their teeth by using neem twigs/datuns, but we wouldn't think those are effective ways to keep our smiles happy and healthy these days!