The phenomenon you are describing is commonly referred to as an "intense interest" or a "fixation." It's when someone becomes deeply engrossed and preoccupied with a specific topic, hobby, or person for an extended period. This intense focus often brings pleasure and satisfaction to the individual, and they may spend a significant amount of time thinking about, engaging with, or pursuing the object of their interest.
Fixations can be positive and enjoyable experiences for many people. They can provide a sense of fulfillment, purpose, and joy. Often, these intense interests can serve as a healthy escape from daily stressors or a means of self-expression.
It's important to note that having intense interests or fixations is relatively common among people, and they can vary widely in nature. Some individuals might become fixated on a specific hobby, like collecting, gaming, or sports, while others may develop a deep fascination with a particular celebrity, fictional character, or subject matter.
As long as the fixation does not cause significant disruption to everyday life, relationships, or responsibilities, and it brings genuine joy to the person involved, it can be considered a normal part of their interests and passions. However, if the fixation becomes overwhelming, interferes with daily functioning, or leads to neglect of other essential aspects of life, it may be worth seeking support from a mental health professional to ensure a healthy balance.