Posts will get locked for inactivity after a certain period of time. As most people who ask questions hre never come back weeks or months later to look for new responses, it is not productive for you to try to work old questions. Yes, they will be available for viewing but not new responses.
Internal search here is a bit convoluted so that is why Bob's excellent recommendation to use a search engine works. A site-delimited search restricts the returns to only those in Apple forums. For example, this search string:
Username +"username”+"2010" site:discussions.apple.com
will search only ASC for one user's post made in 2010.
Replace "username" that is in quotes with yours, but keep the quotes. If you do not need a date search, leave that part out. You can add a subject in the same way the year is added in the example:
Username +"username”+"reset NRVAM"+"2010" site:discussions.apple.com