>if you've ever given a shit about any theories of relativity
>and space time expanse/contraction the ending will NOT be an
>"uh, what" momen

I don't think this is true at all. The "uh, what" moment comes from the convenience of the pieces used to illustrate those concepts. If they wrote this in without the ridiculously convenient bookshelf maguffin, the reaction would be much different.

Further, the whole "It was us the whole time! Specifically me! I was the "They" touching fingers to Anne Hathaway!" idea was incredibly lazy and boring. It would have been infinitely better to use either an entirely different race of beings, or give us an actual glimpse of our higher selves instead using a throwaway line to tell us, hey, I guess it's someone further along than we are and they created this room so we could do this!

The notion that people won't have a "wtf" reaction if they have a clue about relativity and space time expanse/contraction is an incredibly simple-minded approach. The issue is simply bad storytelling.