Plus it probably had to be a familiar face that the Doctor hadn’t encountered yet, it’s no good the Moment picking Tegan or Ace or Jamie, and whilst the Doctor won’t remember the events that happened during Day of the Doctor until he gets to be 11, it does suggest that somewhere at the back on Nine’s mind Rose and Bad Wolf ring some bells, even if only subconsciously, whether you love or hate Rose (or sit somewhere in between) it’s hard to see her as anything other than AN Other companion, at the start at least. I think it fits in wonderfully with series 1 myself without taking anything away from it.
+1