Downfall

Once upon a time there was a drink called Mountain Dew that tasted of citrus and was the exact colour of Ford Premium Engine Coolant.  Dew was virulently caffienated, but it mattered not as a decaffeinated version was available.  Dew Code Red could not ensnare me as nothing beats 7-UP with grenadine for cherryness.  Dew Live Wire tastes orangey great, but not as good as real orange juice.  But it is Mountain Dew Pitch Black that is my undoing.  Dew Pitch Black is grape flavour and probably the reason I'm sat here with a pounding caffeine headache, having drunk nothing more stimulating than vanilla soy milk all day.  Why does grape flavour soda have to include caffeine?  For that matter, why caffeinate orange or cherry?