Remember that slab of dark chocolate that you bought aeons ago? You forgot all about it and left it in the freezer for a very long time. Then the fridge conked out, and you fished out stuff from the freezer, and found this lying in a corner. You know that the product is beyond its expiry date, that it is probably gone all mouldy by now, and that the best course of action for you is to throw it away. The heart will, however, force you to take one last look at it. And that look kills it all for you, probably putting you off chocolate for quite a bit of time.