Take a tall glass. Pour in a finger or two of white rum. Fill the rest of the glass with ginger beer (the fiery cloudy stuff, not that feeble transparent rubbish). Add some ice-cubes and some chunks of fresh lime.
Behold! You are now holding a good mood in liquid form. Seriously, there's something about this stuff... maybe it's just me, but I can't drink it without it bringing a huge smile to my face. It's not like I'm talking about being drunk here, it's more like the muscles on my face are irresistibly drawn into a goofy grin. I think the smell of the lime as you take a gulp might be important, but it's obviously some kind of magic so I don't want to think too much about it in case I break it. Or destroy the universe, or something.