Why do you have dreams of your nephew that passed away over ten years ago?

most likeley you are having these dreams becuase once someone close to you dies you never forget it and you are just dreaming about them becuase you deeply miss them

This dream might have been triggered by something reminding the dreamer of the nephew; his favorite song, a familiar place, or even an odor associated with the nephew. The dream might have occurred on an anniversary of the nephew's birthday, or of his death or on some other important family date. Because dreams are produced by the subconscious mind, the passing of time - even ten years - is not particularly significant.