Learning versus Making Soup
When making soup, as the cook adds ingredients, the first ingredients put into the pot settle to the bottom. To make good soup, the cook has to stir the ingredients occasionally. When adding new techniques to a student's training regime, the first techniques the student learned tend to be forgotten. Similar to a good cook, a good instructor needs to stir the pot by continually having the student practice even the most basic of techniques. Soup is best if it simmers over time. Techniques get better if they are practiced often over a long period of time.