For me, my blind spot has been China. They've maintained their bubble economy for decades longer than I (and a few other smarter people than me) think possible.
I've seen many analysts say (I'm no expert myself so I'd have a hard time judging) that the official government figures for things like GDP and so on cannot possibly be accurate. (And before you ask "Which figures, which years, what degree of inaccuracy?" — you'll need to ask someone who actually knows). Which does make it kind of hard to figure anything out about China's economy from outside.