there's a theory i buy into that dubois managed to forget his memories because he put his head into the tiny ball of pale in the church to erase his memories while drunk after jumping his car over the bridge and then managed to stagger back to his room in the whirling in rags (as opposed to just drinking until he forgot almost all of his memories) and in the process he gained a load of information from it (which is why and can tell you so much info that you have no way of knowing, including stuff from the future)
spoilers
there's a theory i buy into that dubois managed to forget his memories because he put his head into the tiny ball of pale in the church to erase his memories while drunk after jumping his car over the bridge and then managed to stagger back to his room in the whirling in rags (as opposed to just drinking until he forgot almost all of his memories) and in the process he gained a load of information from it (which is why
and 
can tell you so much info that you have no way of knowing, including stuff from the future)
Isn't it
spoiler
High up in the building, to the point where you need to climb to get up there?
spoiler
i could see dubois being able to get up to it given the level of agility and athletic ability he's shown to have through the game, like that one time he "teleports" up the rickety ladder with his eyes closed