This is why you will need to be familiar with the responsibilities and roles the HRM manager plays. Because it deals with people. People are all different. The way you deal with one person may not be suitable for the way you deal with another. What makes one person happy and motivated may have the opposite effect on someone else.
Managers have many challenges they face on the job everyday.
I believe that one of the greatest challenges faced is employee job satisfaction, or rather the lack of it, job dissatisfaction. Dissatisfaction on the job can be a huge obstacle to a supervisor. Trying to get a person to work productively, or even to get them to perform their given tasks, can be a problem if the person does not want to be there. Many people are unhappy on the job but stay because they cannot afford to lose their benefits. Behavior is purposeful, directed towards some end.