class Stuff
  def initialize
    @blah = ""
  end

  def blah
    @blah
  end
end

s = Stuff.new

s.blah << "things"
s.blah #returns "things" - the instance variable was changed

s.blah = "stuff" #returns error - if s.blah is really a reference to @blah, which is a String object, why can't I use the = method?