In school, you can practice basic skills very solidly and learn a lot every day. At school, I will study 2-3 items every day, and there will be periodic assessments. If you don't pay attention to the examination and don't learn, you won't be afraid to learn after repeated practice.

In fact, apprentices mainly work and study in their spare time. But apprentices work long hours every day and have little time to study. It takes a long time to learn a single product well.