And about this:
"Introverted Sensing has a habit of reflecting on the outside "objects", as opposed to just acting on it (Se). This means that we may pay attention to the outside world for a moment, and than stop paying attention. This habit can leave other people feel somewhat unapprietiated. This is because life and the outside world keep on going on without us. We will spend one minute focusing on a person, and then the next ten in our heads."
I can't relate to this either

I always pay attention to the outside world. At least I feel like I do. And what you mean by Se is "just acting on it". Do you mean Se just "registers" everything as facts and does not reflect on their meaning?
Anyways I do have some concentration problems so I might miss some details because of that. But it is not like "1 minute focusing, 10 minutes reflection" like you said. More like "1 minute focusing, 5 seconds shaking my head because I lost concentration and trying to get my thoughts together".