Every baseball team has a coach.
Every figure skater has a coach because he or she thinks winning a game is the most important thing while he or she competes with other rivals. In karate, Kendo or judo, the same. At school, we have teachers.
Well, when we go to an office one day, there is always someone senior to us. Managerial people keep an eye on us so that we don't make a mistake there. They point out the careless errors we made because we didn't think much about the ongoing project. It happens.
to be continued)