The only way that I know how you could see your other posts is by searching for them. When you go to the "Search" it has a block for "Search by Author*" and you just type in your username then sort by relevance or date. There is a limit of 50 topics that can be watched but you can manage those under the "Watched Topic" tab above.
Hope this helps!
SorceressMiklai Owner/Team Lead of: Wizard101 Petnome Project Petnome Pirates
When logged into Wizard 101 Message Boards, you will see your name (account name) at the top and it will be in red. Just by clicking on your name will open up a page that will show all of the postings you have done. You may then click on them to open and read the message board you posted to.