Fun fact this is caused by American chocolate being made with semi spoiled milk!
American chocolatiers figured out that it was very hard to keep a stable milk stock so they found out you could use semi spoiled milk to make chocolate but the milk gives the chocolate a sour taste.
This is why most Americans don't like European chocolate and why most Europeans don't like American chocolate.
Yeah but as an American I'm the one that has to deal with the smell long after the sandwich is gone