"Absent-minded" means that you are physically present, you are here--but you are not paying attention because your thoughts are focussed somewhere else. Your body is present, your mind is absent.

It is normal for everyone to be absent-minded at times. Some people, of course--particularly people who are often deeply involved in some long and complicated train of thought--are "absent-minded" as a character trait.

Notice that there is a somewhat opposite phrase, "presence of mind." (Never "present-minded.") To "have presence of mind" means to be very alert, and to act quickly and appropriately to some sudden surprise. "He saw the glass of milk at the edge of the table, and the child's elbow moving near it. With great presence of mind, he whisked it out of harm's way before the child knocked it over."

Hi Ms. Brightside,

Yes, indeed you can. We can be absent-minded when something slips our mind. It does not indicate a personality trait. 

A personality trait refers to the values or principles that guide a person in his or conduct or interaction with others. Examples of personality trait include: Openness, conscientiousness, introversion and so on. There are more permanent and internal in nature. 

In contrast, external factors such as lack of sleep can cause one to be absent-minded, and is temporal.

Hope this helps.

Cheers,

Lance