Raava implied that Harmonic Convergence occurred long before Wan's time and even implied that there was more than one occurrence. So why does it feel like their world is very old border lining on ancient?Of course, this is probably normal when you take into consideration the age of our world being 4.54 billion years (thanks Google for ending my search right at the top of the page) then if my math isn't a completely and utter failure then 4,000,000,000 / 10,000 would result in Harmonic Convergence occurring a number of 400,000 times prior to Wan.This is assuming that this was their world's age during the time of Wan. If during the time of Korra their world was this old then Harmonic Convergence would have occurred a total number of 399,999 times which I assume includes Wan's time.Of course, my math skills is utter shit so I probably failed hard big time.