In the early 1950s, the Betty Crocker Company introduced a cake mix so that people could readily make excellent tasting cakes at home. No muss, no fuss: just add water, mix, and bake. The product failed. “The cake mix was a little too simple. The consumer felt no sense of accomplishment, no involvement with the product. It made her feel useless.” Betty Crocker solved the problem by requiring the cook to add an egg to the mix, thereby putting pride back into the activity. Adding the egg gave the act of baking a sense of accomplishment, whereas just mixing water into the cake mix seemed too little, too artificial.

Donald A. Norman, Emotional Design: Why We Love (or Hate) Everyday Things

We are such sensitive creatures.