Hi there! I'm going to move this over to the Site/Forum Help board as it's more suited there.
As for the post count, accounts cannot be linked. As of recently post counts were boosted due to a change in board organization, quite a lot of users had their post counts skyrocket. If you've played a lot of forum games in the past, then you may've gotten a post boost. From what I can see your account was actually made in January 2012. Seeing as how old majority of your posts are, you may've forgot you posted them, which is completely understandable. The only other explanation is if you were given the account, but considering you said you created the account, I'd go with the latter.
Hope this helps!