Because the human brain is a universal machine, it contains multiple strange loops that are coarse-grained copies of other strange loops housed in other brains at varying degrees of fidelity. Those you resonate most with in life (family member, a spouse, etc.) you know so well you can almost feel their feelings, recall their memories, and experience the world they would. These can not be explained by mere rote memory (perception is not reception and awareness) but something more closely resembling our own self-hood.
When people pass away they live on, in the sense of consciousness, through these collective copies. The fact that they are imperfect copies does not detract from this simple idea. After all, we wouldn’t say that a book translated from another language is somehow a different book.
From I Am a Strange Loop.