Dave,
It it is simply a matter of finding a recent post or thread, what I often use is the forum's Advanced search feature and adjust the time period to a few days or a week or sometimes a month or so, based on my recollection of when the post or thread might have been entered. To keep from getting too many hits (although selecting a short time period usually drastically cuts back the number of hits), I try to use a keyword, or string of keywords, that will further limit the number of hits. If I remembered the user's name who posted, I use that name in the User's name box.
Peter