i think i cheesed that :D if you go outside where the trunk is, first lower is as far as possible. then stand behind the chest and upper the trunk as long as you can stand behind the chest. then glide to the top of the doorway (hust stand on it then. after that sink the trunk so the top of it is...
So, the shield sliding trick you can use after you meet two guys on the road on your way to the fire mountain or so...i think near a horse break point think (dont know the name in i#english )
For the memory places: i made two random side quests i encountered randomly...after finishing i could...