4. Fromage
In English: "cheese." Even if you consider yourself a connoisseur of cheese (a "turophile," to be exact), you don't really know what cheese is supposed to taste like until you go to France. In the U.S. there are strict regulations on how cheese can be prepared — basically taking out all the good stuff — so the cheese we get here is pretty much "dumbed" down versions of cheese. In fact, some French cheese are actually outlawed in the States because of our silly rules on how cheese is made. So, load up on the fromage... then don't eat cheese back in the States until you forget how great it was in Paris.