The constellations may be simple, but The Doctor is seeing the real ones in his minds-eye and all the space, in-between. The gases, the super-novas, the dust. He for sure seems to be looking at more than what is there in reality.

When Wash speaks out, finds himself being grounded in a sense, "Just The Doctor." Even if The Doctor does have several PHDs from his time spent on Earth. He was calling himself, The Doctor long before that. Back on his home planet of Gallifrey.