I'm from the UK (for my sins) and personally, I'd say my geographical knowledge is probably above average, though I make no claim to be some kind of genius. I studied Geography up until Year 9 at school (ages 13-14 for folks who use a different system), but given that a lot of that focused on physical geography (stuff like rivers and erosion and all that jazz), most of what I've learnt about "proper" geography is either self-taught or picked up the same way I'd pick up any general knowledge.
I just did the "
Countries of the World" quiz on Sporcle and got 182/197. A few years ago, I got bored, so I decided to learn all the US states and state capitals. According to
a different quiz on Sporcle, I can still name them all!