It's important to note that we all miss appointments, we
all prefer to do activities that interest us, we all
occasionally stop listening to people mid-way through a
conversation, and we all struggle to pay attention to
boring jobs. These aren't signs of a disorder, these are
just facts of life.
While it is normal to "zone out" and struggle with boring tasks at times, if a person struggles with attention-related tasks on a long-term basis to the point where it negatively impacts their life, that points to some kind of behavioral issue.