In Harry Potter and the Half Blood Prince (ch.- Chapter 9), Slughorn says (emphasis mine):
"I've prepared a few potions for you to have a look at, just out of interest, you know. These are the kind of thing you ought to be able to make after completing your N.E.W.T.s."
One of the potions in question is Amortentia - the most powerful love porionpotion in the world. Why exactly would anyone in the wizarding worldWizarding World ought to have to be able to make it?