A phrase relating to a plot twist in Final Fantasy VIII, in which it is revealed that all of the main party -- plus the mysterious Ellone and minus Rinoa -- were raised in the same orphanage, by the very sorceress they are fighting. They all forgot this because of the use of Guardian Forces, which occupy the same portion of the mind as those memories.
Except that Irvine, who didn't use GFs, knew that everyone ought to recognise each other, but never bothered to mention it.
This is widely considered to be one of the silliest plot twists ever created, and is used by trolls (and some fans of the game -- and by pretty much anybody, really) to poke fun at Final Fantasy VIII.
Popularized by Amazing Telephone's original usage in a FFVIII story topic, like so:
"HAY GUYS," Diablos boomed as he floated past, "WE ALL GREW UP IN THE SAME ORPHANAGE LOL"
KleenexTissue50 currently owns the awesome alt account "Same Orphanage".