His mentor will wait until the right moment to tell the student what he needs to hear. One drawback to real-life situations is that they often do not have mentors, in which case they leave out both teaching and history. Trying out a new role without advantage of a mentor can be a slow, frustrating way to learn. It can lead to bad habits or failure to synchronize actions. Teachers provide challenges, encourage risk taking, correct errors, and provide context.
Apprenticeship requires the expert as well as the apprentice.