Peter's seperated from his timeline, I don't know why they havn't asked him what he remembers, but it probably wouldn't be of any significance.
What we have now is two universes where nobody recognises Peter as an adult because on both sides in this timeline he died as a child, on "our" side because of the illness and one on the "other" side because the Observer didn't pull him out of the lake and he drowned.
In this timeline though, David Robert Jones is alive (because in the other timeline he was killed by Peter) and he is responsible for creating the new human-shapeshifters.
Peter is trying to get back to his own timeline (the one all previous seasons take place in), at the moment we have 4 universes;
Original universe (original timeline)
Alternate universe (original timeline)
Original universe (alternate timeline)
Alternate universe (alternate timeline)
It's bloody confusing, but with some well written episodes, it could be quite special!
