Our house is approaching 100 years old and has lathe and plaster walls that have seen better days. It also had 4 rooms of really ugly wall paper when we moved it, it took a lot of work, but that's all gone now. The worst was the wainscoting in the dining room that had old wallpaper behind that had just been cut off at the top when they put up new ugly wall paper (20+ years ago). So I decided to take off the top piece of trim from the wainscoting, but it wasn't just nailed to the wall, it was glued as well and took a bunch of plaster up with it.
But that wasn't as bad as the master bedroom which had a wallpaper border around the middle of the room with a piece of trim above and below, which were all glued to the wall and impossible to get off. I ended up having to patch the plaster in two strips around the entire room.
Old houses, yay!