Yep, it's also naturally occurring in all sorts of Asian food (due to soy or something) if I understood what I read correctly. That's why "no msg" Asian food tastes so awful.
They are an acquired taste. That isn't a joke by the way. As you decrease the amount of sugared soft drinks you consume and switch entirely to diet, it won't be long before the ones with real sugar start to taste gross and the fake sugar tastes good. That's what happened with me anyway.