"A harmonious passion refers to a strong desire to engage in the activity that remains under the person's control." This is mostly obtained when the person views their activity as part of their identity. Furthermore, once an activity is part of the person's identity then the motivation to continue the specific hobby is even stronger. The harmony obtained with this passion is conceived when the person is able both to freely engage in or to stop the hobby. It's not so much that the person is forced to continue this hobby, but on his or her own free will is able to engage in it. For example, if a girl loves to play volleyball, but she has a project due the next day and her friends invite her to play, she should be able to say "no" on the basis of her own free will.