I haven't had chocolate for ages but can very easily just have a small bit and leave the rest.
Wine, I can easily not drink at all (don't generally drink in the week and haven't done for ages, years really, stick to this 85%+ of the time) but can easily drink a bottle or more on a Friday/Sat night. But red wine, oddly, I can easily just have one glass, it's white / Champange I neck.