In the Newbery winner, The Giver, Lois Lowry creates a scene that I want to memorialize here. It is two thirds to three fourths of the way into the book, so, by that time, Jonas has been selected to become The Receiver and has already received substantial training in becoming such. For some reason, the community declares an unscheduled holiday, and Jonas is delighted, presumably because he's been working so hard in receiving. He heads off to find his best friend, Asher. He finds Asher and a group of other children playing together, including Fiona. They are playing war, shooting at each other and acting shot. It disturbs Jonas, because he has already received the memory of war and its pain and other horrors. Therefore, his counter with his friends, Asher and Fiona, doesn't go well. Jonas discovers that he cannot relate as well with them now, because they don't have the memories of war, like he does.
For an undocumented alien (I'm thinking about Aljehandro here), such an experience --- at least in some part --- must be familiar with respect to trying to have or maintain friendships with citizens who don't constantly face the same threat of discovery and deportation. Of course, what is involved is an ability to empathize. In order to empathize, experience is required. A memory of that experience is essential in order to fully understand. Of course, the experience doesn't have to be firsthand. It can be experienced vicariously, for example, by reading a book, or seeing a movie, etc.