>Just don't know where to start searching. Archives??
To access the archives, go to the catalog, there is a text link in upper right hand corner "Archives"
If you remember the date, you can go to the week and it will show a list of all threads that fell off the catalog that week.
It's arranged by month, and then weeks in the month. It's a good way to search for your case because it shows the thread title, whereas the archives on the spreadsheet & MA's site do not.
Hope that helps and HAPPY BIRTHDAY! :)