You are somewhat lost in your own mind most of the time and tend to not notice things like people talking to you or things that require your attention. This trait should be used whenever attention and perception is of importance, provided that you haven't set yourself to finding something.
For instance, the trait should not be used if you are actively looking at or for something, but could be used when something unexpected randomly happens, or a Perception check out of the blue. The trait does not affect your ability to focus and analyse things that you have already discovered.