I've had the same incredibly intense deja-vu from walking through a certain building the first time at my university in South Australia, realizing soon after I

I've had the same incredibly intense deja-vu from walking through a certain building the first time at my university in South Australia, realizing soon after I had played a custom map/level of that same building years earlier in the Half Life 2 engine. One of the weirdest feelings... I fully expect many such moments in San Francisco after so many hours of teenage youth spent playing GTA: San Andreas online! :)