Really? We have it in Spain too (Bitter Kas), in the UK there's Angostura Bitters which is really refreshing when you add a few drops to a glass of lemonade.
There's such a history of bitter drinks
http://en.wikipedia.org/wiki/Bitters
And it's so widespread across the world - especially in HOT countries and regions - it's hard to think of them as weird. They are so good at stimulating flagging appetites.

If you end up craving a bitter taste on a particularly hot day there was a Japanese recipe I came across some time ago that I really enjoy. The gist of it was that you take a bitter melon - goya in Japanese

finely grate some and just add it to the soda of your choice.
You can add it to club soda but I like it mixed in with a sweeter carbonated drink.
Here's a ready made version from Japan

I'll take bittermelon soda over melon soda any day